. >>> jeff rossen is throwing a bash with an open bar and police on hand to put drinkers to the test. a social experiment that may make you think twice before getting behind the wheel. >>> trending online, what stories were clicked on the most this year on our website, www.nbcwashington.com. >>> pope francis turned 77 years old today. he marked his birthday with hugh mi millty. it's his trademark. afterwards, they ate breakfast together at the hotel. the pope has already blown out his candles on his cake presented to him by children at the vatican saturday. >>> death, devices and celebrity fueled the top request from google. the deaths of famous men, number one, nelson mandela, second paul walker who died in the car crash. the iphone 5s finished third. then the death of cori monteith. he died of a drug overdose over the summer. searches for the harlem shake rounded out the top five. they are the top searches for google internationally. walker took the top spot and the boston marathon bombing was second. here is the list of the topmost clicks on www.nbcwashington.com. the top was the s

jeff rossen shows us a state of the art computer system that can take control of a train in a crisis.: officials believe speed was a factor when this commuter train took a curve and went off the rails. but, experts claim revolutionary technology could make accidents like this a thing of the past. >> state of the art collision avoidance technology. >> reporter: it's called positive train control or ptc, a system of sensors on the rails and inside the locomotive. using satellites to track the trains movements and prevent many accidents caused by operator error. if the train is going too fast, the computer warns the crew. if the engineer doesn't slow down, the computer activates the breaks. ptc helps prevent collisions, too, stopping the train from blowing through red signals if the operator is distracted. >> it will save lives. both crew members, passengers and maybe people along the wayside as well. >> reporter: like in spain this summer when this train threw off the rails. the operator took the turn at nearly twice the speed allowed. 79 people were killed. in massachusetts, this trans

nbc's jeff rossen tells us what he found. >> it's the middle of a school day and i'm a stranger walking in off the street. >> good morning. we are testing school security in new jersey with hidden cameras rolling. at this elementary school there's a buzzer. >> hi, my name is jeff. want to make an appointment with the principal. they let me in. but before you get to classrooms, there's another locked door. a staffer has to physically escort me to the office. you can't walk around this school without getting signed in first. so pretty good. >> at the next school security is even tighter. a guard intercepts me before i get to the door. >> i'm going to need it? >> yeah. >> reporter: we were encouraged at four out of five schools we visited. we were kept far from kids and classrooms. but whaatch what happens at thi elementary school. >> hi, good morning. they don't ask for my name and no one is here to escort me. the school's policy is for visitors to go to the office. i turn down this hallway looking for it and within seconds -- there are classrooms on every side of me here. there is a clas

today's national investigative correspondent jeff rossen is here with more. good morning. >> reporter: good morning, no official cause of this accident over the weekend but investigators are looking at speed and possible human error here. now there's a state of the art commuter system that can literally override the engineer and take control of the train to make sure it's not speeding or going somewhere it shouldn't. this morning, the federal government wants it installed nationwide to make us all safer. officials believe speed was a factor when this commuter train took a curve and went off the rails. but experts claim revolutionary technology could make accidents like this a thing of the past. >> state of the art collision avoidance technology. >> reporter: it's called positive train control or ptc. a sophisticated system of sensors on the rails and inside the locomotive. even using satellites to track the train's movements and prevent many accidents caused by operator error. if the train is going too fast, the computer warns the crew. if the engineer doesn'

we have jeff rossen at a target in boynton beach, florida. jeff, good morning. >> reporter: one of the biggest hacking security breaches of credit cards in u.s. history. when came to target during thanksgiving and a few days ago when you went to buy something and swiped any credit or debit card at the checkout counter that is when police believe the authorities got your information. and customers are getting angry this morning. reports of people calling target, going on target's website, having a hard time getting in touch with the store and so overnight in response, target sent out a e-mail blast to customers saying your trust is a priority and we deeply regret the inconvenience. a lot of people were worried about this. this morning we are going to answer all of your questions and show you how easy it is for the thieves to use this information to go on a shopping spree posing as you. >>> the u.s. secret service is now leading the information into this massive security breach affecting customers at all target stores between november 27th and d

jeff rossen is here to expose how they do it. good morning. >> reporter: good morning.used car you look for the price and the condition. you want a car with lower miles. it's more reliable and lasts longer. criminals have been tricking people for years rolling back the mileage and then selling you the car for more money. now police say the scam is growing. according to a new report nearly 200,000 car odometers are rolled back every year milking americans out of 7$760 million. we're under cover watching this car sell from across the street. the ad says it's a great luxury sedan with 85,000 miles and that's what the odometer shows too. but this car has a secret. >> it has 250,000 miles. >> this is online and somebody could buy it. >> reporter: that's right. 250 thousands. nearly triple what the odometer says. so investigators from california's dmv set up this sting posing as a buyer. as the seller shows off the honda, he has no idea he's about to be arrested. we're there as police move in. authorities say he has been part of a major odometer roll back ring. >> jeff rossen

>> jeff rossen. >> they let me in but before you get to classrooms there's another locked door.hysically escort me to the office. >> you can't walk around this school without getting signed in first. pretty good. >> reporter: at this next school, security is even tighter. a guard intercepts me before i even get to the door. he demands my i.d. >> i'm going to need it? >> yeah. >> reporter: we were encouraged at four out of five schools we visited we were kept far from kids and classrooms. but watch what happens at this elementary school. >> good morning. i'm here to go to the office. >> reporter: they don't ask for my name and there's no one to escort me. the school's policy is for visitors to go to the office. i turned down this hallway looking for it and within seconds. >> there are classrooms on every side of me here. there's a classroom here. the gym is right over here. another classroom over here. easy access. >> reporter: i'm still looking for the office and stop at this classroom for directions. >> where is the office? >> if you go down the hall and turn to the right it's

jeff rossen and his team set up a social experiment that might change the way you behave.rning to you. >> good morning. real wake-up call for all of us. this is of course party season. a lot of us think we know our own limits. i can have a couple of drinks and if i'm not suring my word or stumbling, i'm fine. how many of you have gotten behind the wheel after drinking at your holiday party? this morning our social experiment will open your ice. you can really trust yourself? we're throwing a holiday party. and the electrliquor is flowing. we invited this group of friends to a restaurant and told them we're doing a story about holiday drinking. what they don't know? >> blow hard. >> reporter: after the party, this local police officer working with us is giving them breathalyzers. and field sobriety tests. >> seven, eight, nine. >> reporter: show of hands. how many of you feel in control of yourselves? coordinated? most of you. this man told us he'd even be okay to drive right now. you'd get behind the wheel? >> why not. >> reporter: authorities say too often people lose tra