Is Big Brother Just A Distant Cousin? Careful when you post that tweet - the FBI might be watching you. Or, then again, maybe not. In an age of heightened awareness over terrorist activity, grave warnings about hackers stealing personal data and concerns over Facebook privacy, there is yet another alarming trend: folks suspecting an overlord watching their every move. Web hysteria has grown to a fever pitch in recent months, with increasing chatter about social policing that is way overblown. Here are the top four myths, and whether they have any basis in reality. Myth #1: The FBI monitors your every tweet This one sure sounds likely. After all, the NSA just broke ground on a $1.5 billion cybersecurity data center in Utah, presumably to track the activities of everyday citizens. Many suspect the FBI is watching for buzzwords like "bomb" or "nuclear" when you tweet, and that it can access Twitter servers. The reality is a bit less worrisome. The FBI does not scan every Twitter feed for code words, which would require an enormous computing effort, FBI spokeswoman Jenny Shearer told FoxNews.com. She said the agency's usual practice is to look into the matter if it becomes aware of a threat on Twitter. That's quite different from scanning every tweet looking for terror suspects. Myth #2: Teens routinely snap illicit photos and post them on the Web The fear that teens are using smartphones to take pictures of you might be related to just how many teens even have phones. Many new models, from the iPhone to several Android phones, can snap high-res pictures and video. But in most cases, the phones emit a loud click when you take a photo. On the iPhone, for example, you can mute the audio, but the phone still makes the shutter click. Several apps, though, like SpyPic for iPhone and Silent Spy Camera for Android, do let you take silent photos. Still, there are few reported cases where teens have been arrested for this activity. Paul Henry, security and forensic analyst at Lumension, says he's never had a case where a phone contained illicit photos taken without someone's consent. He has heard accusations that people are doing that, but during the investigation he has found that there were no photos taken. And that makes sense: even with a silent click, we usually know when someone is snapping a photo. Henry says there is cause for concern with consensual photos being taken and then posted on the Web. Myth #3: Facebook tracks your Web visits - even when you're not on Facebook Everywhere you look on the Web, there's a Facebook "like" or "recommend" button - even on this story. When you click the button, you're telling your friends you liked the story. What you may not realize is that you are also telling Facebook a few things about your Web visits. Yet new findings by Ireland's Office of the Data Protection Commissioner tell a different story. The study, which looked at actual Facebook code, found that the social network does not build a profile of users and does not send targeted ads to users based on their Web history. Facebook spokesperson Jaime Schopflin said the social network uses information from "like" buttons to analyze site performance and make code changes based on the collected data, but without any ties to specific users. "The Like button is not used to gather information about specific people to know their interests for the sake of advertising," Schopflin said. Myth #4: Your company (or ex-boyfriend) is spying on you Each week, there seems to be another rumor about someone spying on corporate workers or recording video of you at home with a laptop webcam. One widely reported case in Pennsylvania showed how the IT staff had installed a program that could record video and snap photos of students at home. Yet, while some of this secret spying does occur, it's not widespread. Just as someone snapping photos of you in public is fairly obvious, it's easy to tell when a laptop is recording video, since the laptop cover has to be open and facing you. Many laptops use a red light to show that the webcam is recording or emit a sound when the camera snaps a photo. Installing spy-recording software on your laptop without your knowledge and posting the results on the Web is also illegal. Why do these myths exist? In some cases, they are spread by security professionals who warn constantly about imminent dangers. Those same analysts then charge high fees to explain what to do about the problems, or sell software meant to protect against the so-called dangers.