. >> tonight on "20/20" -- unfriended. a popular teenage girl lured from home for a mysterious joyride in the middle of the night but she never comes back. >> i was scared to death. i didn't know where my baby was. >> does this creepy game by bffs recorded on a cell phone. >> would you rather suffocate or get shot. >> shot. >> drowning or suffocating? >> suffocating. >> tonight, "20/20" taking you inside a jaw-dropping mystery. >> it's a race against time at this point. >> and the secret world of mean girls gone wild. >> give me the phone. >> no. this is over. this is over. >> hurry up. >> from cryptic messages on dpais and twitter to a real-life crime scene in the woods. >> skylar is screaming why. >> what happens when three's a crowd and one person gets cast aside. what secrets do they have and who do you believe when pretty little liars seem to be everywhere. >> her words were i have to tell you the truth about what happened last night. >> tonight, what can happen when you get unfriended. >> best friends from hell. ther

isn't that what the unfriend button is for? you just click the unfriend button and then-- no france you don't just hide them from your time line. as the cow ard away. oh, man. this sucks. je suis confused. arresting someone for saying something days after a rally supporting the right of free expression it's a little weird. maybe if we naw pore about the culprit. >> he is very controversial am he had a tour cancelled last area because of this anti-semitic routine that he does. >> so french authorities had to cancel his tour because he does an anti-semitic routine. shouldn't that tour have been cancelled because no one was buying tickets? (laughter) for the anti-semitic comedy show? why-- shouldn't that been a marketplace situation. shouldn't this have been the phone call, hey it's me your agent. morty bernstein, i don't know that for a fact. >> yeah yeah i'm sorry your tour has been cancelled yeah i know, i thought it was funny too t it's just that all that racist anti-semitic [bleep] you do, it turns it out people think that su

it happened online, when they clicked the unfriend button. why?ixed up like food and vegetables in a juicer like this. >> we did a thing like juicing. it's real healthy for you. she had posted that they weren't into the juice scene. >> reporter: but the neighbors disagree. the posts are long gone, but there's no doubt that they claim was written squeezed the life out of their friendship. >> they said it gave us diarrhea. >> reporter: it juiced up the tension already simmering over this man, another neighbor feuding with rick over trees. when you saw that neighbor having problems with rick, what did you do? >> i intervened. >> reporter: leading to the wall. they created what today is sort of the berlin wall of san antonio. a fence build by yolanda's husband. a nearly 12-foot behemoth. and forth. it's a monument to family hatred. >> at the center is this 12-foot-high corrugated metal fence. >> reporter: and one big headache for the cops. >> we're back and forth, over and over again. >> reporter: and for the most part, what they do isn't against the

is the market out of its mind or should you unfriend the stock? plus, the chaos and the company that i call the scientists of the oil patch. hey, why don't you stick with "cramer"? >> don't miss a second of "mad money." follow @ jimcramer on twitter. hash tag, send him an e-mail to madmoney@cnbc.com. or call us. miss something? head to madmoney.cnbc.com. so, how do you feel about cash back? i would not say i'm into it. but let's see where this goes. [ buzzer ] do you like to travel? i'm all about "free" travel, babe. that's what i do. [ buzzer ] balance transfers -- you up for that? well -- unh. too soon? [ female announcer ] fortunately, there's an easier way, with creditcards.com. compare hundreds of cards from every major bank and find the one that's right for you. creditcards.com. it's simple. search, compare, and apply. [ ice rattles ] >>> how can one man make such a difference at a $90 billion company? how can the sacking of don thompson as the ceo of mcdonald's and the replacing of easterbrook, relatively unknown, and caused it to rally 5%

we'll explain why you should wait though, before you start unfriends people. >>> and in france, a police office targeted. . ♪ ♪ ♪ >>> a developing story in france. police arrested two people after they drove a car into a police woman guarding the french presidential palace. the car was going the wrong way on a one way street. france is on high alert after violence that left almost two dozen dead. police say last night's incident is not connected to those attacks. france is getting more involved in the international fight against terrorism. the president there is sending an aircraft carrier in the middle east to join american trips fighting isis. france is are already carrying out air strikes. meanwhile the justice ministry has ordered a crackdown on hate speech. 54 people have been arrested since last week's attack for anti-semitism and glorifying tim. >>> one week after that shooting massacre at "charlie hebdo," it is releasing a new issue. the cover shows an image of the prophet muhammad. muslim communities have could not condemned it. al qaeda has claimed responsibility for the attack

if he changes facebook one more time i'm unfriending him. >> i will unlike him. is in unli >>> a limo driver shot dead inn front of the girl friend, a gunman still on the loose what police mow so far in a live report. >>> plus desperate search for missing college student comes to an end. shane montgomery found over the weekend in the schuylkill river. what investigators are waiting to hear about from the medical examine er. >>> and what happened with the eagles, all kind of front office changes happening behind the scenes. does chip kelly have too much power? that is question people are asking. >> why did he trade desean? i will have big daddy graham about that one. if you trade desean, you better win. >> more important than that from last night governor christie back in the box. >> i know. >> all of the big hugs high five's and all that. >> governor christie's brother is weighing in on twit era and facebook. it is just ugly. >> it is monday, january 5th, 2015. >> so, it is chilly outside. >> yes. >> but nothing like what it will be like on thursday. >> yes good

if you don't want someone to see something, unfriend them or block them. >> or maybe don't share so muchooking all the time or something. >> when your binge cyberstalking, like how we binge netflix, it's a problem. when you know what they're having for breakfast. when you know where they're at on friday night. or if you're stalking the new partner of your ex, that's a problem. especially because social media is a distortion of reality. we're only posting the best pictures. when we're on a vacation. doing something great. you could become depressed if you're starting to -- >> you're not seeing the guy you broke up with. you're seeing this version he's putting out there. so let's help everybody. if you're stuck in that thing where you just want to get online and thinking, how is he doing? why is he dating her? and sounding more and more like a single white female, what can you do to move on? >> don't go fbo. facebook official. especially for the younger generation. we're so quick to change our relationship status and say, in a relationship with chelsea krost because then when you break up