for world car free day — organisers want to promote greener travel alternatives. and now on bbc news, victoria derbyshire takes a look back at some of the highlights from her programme this week. hello, welcome to our programme. for the next half an hour, we'll bring you some of the exclusive and original journalism we've broadcast over the last week. first, countdown presenter rachel riley told this programme she's blocked over 1500 people on twitter because of the amount of abuse she receives. a group of presenters, politicians and other high—profile figures are calling on others to stop engaging with online trolls in an attempt to stamp out cyber hate. among those making the plea are gary lineker, the mayor of london sadiq khan and richard

osman. they all endorsed a new guide on how to combat online abuse. published by the centre for countering digital hate, it advises people not to engage with any form of it and, instead, block and, if necessary, report those guilty of it. rachel riley's received tweets like this... excuse the strong language here. but does the decision not to engage with tweets like this allow online trolls are to spread hate and misinformation and challenged? rachel riley started by telling me why she's blocked so many people online. i didn't realise, when i accidentally kind of stepped into the realm of political trolling, with anti—semitism,

that that is what... the trolls are exactly the same. that's what they're after, they're publicity and they purposely target public figures to try and get some of our followers to read their doctrine, basically. if a public figure has, say, 500,000 followers, and you retweet someone and 95% of your followers say, this is appalling, this is disgusting, this is racist, this is horrible — that is 5% or 25,000 people that you are exposing to a racist and i do not want to do that, so i've got no need to see what these people are writing. if someone said that to me in the street, i'd walk away from them, so there's no reason why i should get it when i'm at home with my cats or husband or whatever i'm doing. sure. and we gave an example of some of the abuse you have received, but it is across a whole spectrum, isn't it? just give our audience an idea. laughter. i mean, you have to laugh to defuse it because part of this paper says, you know, being a victim breeds more victimhood. they will attack him.

but i've had all sorts. i've had people denying myjewish heritage, saying that my dead granddad would be disgusted by me. i've been compared to abu hamza, a prettier version of abu hamza, a nazi, a white supremacist, a paedophile enabler. i mean, you name it, these people are saying it. and i don't need to give them any oxygen. it's pointless. you first came across a campaign called the boycott rachel riley campaign when you learned you were pregnant. what effect did that have a new? it really focused me to realise that blocking people is not weak. it is actually strong because it is human instinct to defend yourself, but, you know, since being pregnant, anyone who has been there will know, you have a bit of sugar and your baby starts wriggling straightaway. you're in a great mood all day, your baby is kicking and having a great time. i had a stressful weekend on social media and my baby went quiet for a couple of days and that made me realise however

mentally strong i am, there is a reaction, there is a fight or flight, there is adrenaline, there is hormones that go through your body and now i'm sharing them i absolutely do not need to give that maybe by any stretch. ido i do not need to give that to my baby. i do not need to give that to my baby. there is just no cause for it. what they are looking for is a reaction of any kind because it boosts their numbers. what you say, actually, is that defending yourself online is a trap? it is absolutely a trap and i think of it in the way that my mum used to say to me, if you have got an itch, in society that we're actually constantly scratching, allowing it to spread and that is what is driving the increase in hateful ideas and hateful speech and this attitude that is sort of exemplified by the kind of nastiness that we see in politics today. they have a right to free speech, they have a right to hold their disgusting opinions, but we have no duty to hand them a megaphone and to allow them to broadcast it to even more people. 0k. and actually, by blocking them, or that we're saying

is that we do not want to have to listen to it ourselves as individuals. we do not want to have to listen to hate being targeted at us. there is no duty for any individual to suffer the anxiety and, really, the pain of being abused based on their identity or for any reason whatsoever. social media, now, it means that anybody can contact you when you're getting out of bed, going to bed, carrying on about your life and it is targeted. they have whatsapp groups where they decide what they want to talk about who they want to target that day and if you make a... if you do a post and you get 50 angry people telling you that you are an idiot, you're wrong, it has an effect on you. but that is what they are trying to do, they are trying to use a small number of people, most of the time anonymous people, anonymous accounts, to change you, to change the way you act, to change the way you speak and it does provoke reactions that are not necessarily that helpful, so this report has totally changed the way i use social media and its so much better.

i want to mention a couple of tweets that you have sent to people. you can tell me whether you think this is trolling or not. laughter. injanuary of this year, you told george galloway to f off. idid indeed. after he criticised you on twitter. you often... you have used strong language to call out others with whom you disagree. you tweeted this aboutjeremy corbyn. .. "jeremy corbyn is an anti—semite, pass it on". no matter how you feel about how he has handled anti—semitism or not in the labour party, is that an example of trolling? so, that's an example of my reaction to trolling because the george galloway tweet came in the week that the podcast came out so that came in a week where i'm not sure how many thousands of messages of abuse i got and at that point, george galloway, before having seen what i had said, added to it and i... that was an example of me accidentally amplifying a troll. in terms of campaigning againstjeremy corbyn, i have posted countless bits of evidence and, in the end, you know, people are trying to use

humour, trying to use any way they can to get this message out there because thejewish community are very scared. they're worried. people considering leaving the country and it's a hugely serious issue. neville tweets this, "while it's very wrong, the abuse that rachel receives, it is not only high—profile people who get abuse. because i want a people's vote, says neville, on brexit i've had to blow over 200 people on twitter because of the abuse i have received. dave used to be a troll. he e—mailed and said 15—20 years ago i was a troll. i was trolling pretty much everyone i didn't like. but people started ignoring me. it got boring and not funny anymore, plus very hurtful to them. now i have matured and i do not do social area and i still regret my behaviour. well done, dave. and brian says, troll is a sad little people have too much time on their hands and need to get a job. don't acknowledge them, itjust gives them oxygen. next, we exclusively reveal that more than 60 politicians, academics, barristers and campaign groups

are calling on police forces and private companies are to stop using live facial recognition technology for surveillance immediately. this kind of live tech can scan your face as you're walking down the street and check it against a watchlist in real—time. so it is not like facial recognition used that passport gets, for example. critics say that the live element means that it is inaccurate, intrusive and infringes on an individual‘s right to privacy. those that make and use the tech say that it is helping to protect the public and can catch people like terror suspects. so what exactly is the technology and how does it work? this from our reporter catrin nye. many of us have already used facial recognition technology. so, this phone registers my face and then it can unlock using it.

automatic passport gates also use it and come around the world, police forces and private companies are adopting this technology. but privacy campaigners argue that the tech has moved faster than any regulations to control it. and it is being adopted in the uk before it has been properly scrutinised by politicians. live facial recognition that works in real—time has worried people further. where you walk past the camera and — in real—time, without you even necessarily knowing about it — yourface is being checked against the watchlist. in the uk, there have been trials of live facial recognition technology by police in london and south wales. this was the last of ten trials by london's metropolitan police and was filmed by the bbc click team in january. how would you like it if you walked down the street and somebody...? when one man covered his face, things got heated and he ended up with a £90 fine for what police called, "disorderly behaviour".

if i want to cover my face, i will cover my face. it is not for them to tell me not to cover my face. i've now got to £90. there you go, look at that. thanks lads, £90. the police here argue that not trialling the technology could see them left behind. we are completely aware of some of the concerns that are raised and what we're doing with these trials trying to understand those better so that we can actually protect human rights, but also keep people safe at the same time. i've come to a private company supplying this tech to see how it works. digital barriers provides facial recognition worldwide, mostly to the police, the military and other law enforcement organisations. what we're able to do is recognise people against watchlists as they walk past cameras, essentially. they have set up a demo for me — two of their employees are working in the street outside, the system has their photos,

they are on a watchlist, so it should — and it does — identify them. every time a face is detected, the facial recognition technology will compare that face against the watchlist and if it detects a match, you will see that match recorded. and what is happening to the people who are coming up as unknown? so, they are ignored. so they are not recorded, they are not registered. on this piece of kit, you can adjust to the threshold of accuracy at which a face will be recognised. basically, change how close they face has to look to the picture you have on record. this depends on how much you want to catch a person. if you believe that there is an active terror cell operational any mainline railway station, at that point you might put the threshold low. if all you're doing on a busy street is looking for people who potentially have skipped bail, then at that point it is to set the threshold higher. we also put my image into the system to try it on a new face. so she has been picked up consistently. a very good level of confidence. it is not completely reasonable that

people are worried about the hugely expanding use of this technology with very little public scrutiny? so let's think about it in real—world use cases. so i am in the counterterrorism business and i know that there are five individuals in central london, where we are sitting right now, that want to do harm on a massive scale to the public. would you have public support to use facial recognition to try and intercept that group of individuals before they can do harm? i would suggest, almost categorically, you would. i would give you the opposite example. an individual has been kicked out of the pub for drinking too much on a saturday night. the pub has taken a photo that individual. should that individual then be prevented from getting into that establishment and other establishments because of that incident? i think you will have very little public consent for that example. unfortunately, there is no clarity, no regulation, that governs either case. but privacy campaigners see things differently. big brother watch released this statement, along with more than 60 politicians, academics, barristers and other campaign groups,

asking for an immediate stop to the police and private companies are using this technology for public surveillance. i, for one, think that we do not want to live in a surveillance state. so, what we're doing is putting this to government and parliament to say, please can we open this debate and had this conversation, but, for goodness' sake, whilst that conversation is going on, there is now a crisis — a surveillance crisis on our hands that needs to be stopped urgently and that is what everyone who is signing this letter is asking for. in our demo at digital barriers, the computer was often slower at identifying the black women in the street than the white man. this does not mean that the system was mis—identifying her, but it does mean, in this instance, that it was at least slightly less effective on darker skin. so there have been a lot of studies that show that facial recognition systems do not work as well on people of colour and women, generally. this can be for a number of reasons,

such as, colour contrasts on the faces of people of colour and also the systems can be confused by cosmetic make—up and also some of these systems have not been trained with enough diverse datasets of people from different demographics. you could see a situation where you are identifying innocent individuals who are from a particular minority, for example people of colour, which means that there would be questioned by the police, even though they are innocent and they may even have their details and picture kept on record. despite having committed no crime. he thinks that the government should implement a long pause on the roll—out of this technology while all these issues are resolved. i think there is a much deeper issue, which is the issue of the face veil. i think a facial recognition technology is rolled out by the police in the uk, it will lead to an effective ban on a face veils. the king's cross estate, the private area of land containing

the station and a load of shops and offices has also been at the centre of facial recognition controversy. it was recently revealed that the owners of the estate had been using the tech on the public here without their knowledge. and then, to make matters worse, it came to light that the met police and british transport police had supplied the company with images for the database. both police forces had initially denied any involvement. so everything about this is happening in a vacuum of regulation and oversight and clearly public knowledge. when you speak to people, there are thousands of people walking around right now, when you speak to them, how much they know about this? nothing. they know nothing about it. i have looked around the area for signs, any kind of information about what has been going on and there has been absolutely nothing. at digital

barriers he would not reveal to us who he sold the technology to. for some people that is the most important piece of information. who is it that you have demonstrated the technology to —— who have you given it to? let's be very clear i agree with you. i think the test cases should be public. my point is it is not for me to start talking about organisations that use our technology or from others. organisations that use our technology orfrom others. it organisations that use our technology or from others. it is for regulation and those organisations to make it known. the other police force that has been trying that is south wales police. as a result they we re south wales police. as a result they were taken to the high court by a man who was caught on the cameras. just this month, the court found that their use of facial recognition was lawful. that decision is now

being appealed. tony is uk surveillance commissioner. he thinks there must be a set of strict standards in place governing how these technologies are used and before there's any formal adoption by police forces. i think there should be a single standard that incorporates the type of equipment, a standard around exciting, around its efficiency and effectiveness. i suppose you might say what is an appropriate false hit rate that is tolerable. if we were to live in a police state, then we would not be able to do lots of thing. —— we would be able to do lots of things. if we put cameras in people's bedrooms, we would be able to stop abuse. will be able to stop bad people and catch bad people. just last week a group added their voices

to stopping this technology. this is a debate that is only getting louder. the home office told us they support the police as they trial new technologies to help them locate and identify suspects and criminals. finally, the young men who suffered from a range of serious food allergies. he was selling his 18th birthday at a restaurant in 2017. he told the staff that he had allergies before ordering chicken. soon after eating, the teenager suffered a devastating allergic reaction and he died tragically within hours. it was later discovered that the chicken that he ate was marinated in buttermilk which he was allergic to. the coroner ruled that the restau ra nt the coroner ruled that the restaurant misled him into thinking it was safe for him to eat while failing to highlight that the dish contained dairy. now a new law is

being called for. and they have not ruled out suing the burger chain. he a