Ever get a strange feeling that someone's snooping around on your facebook without your consent? Chances are you probably have a weak password so changing it should be enough to solve your problem, but then again if you're anything like me finding out exactly what gossip girl(s) is/are snooping around and then getting back at them is worth much more. Unfortunately, unlike GMail, facebook doesn't provide you a list of IPs of the last x logins, so finding an unwanted connection isn't an open and shut case. That's not to say that there aren't options available to you, after all there's always more then one way to skin a cat.
First things first, test your hypothesis. No point in going through all the trouble if no one really is snooping around. To do this, simply deactivate your Facebook account. If anyone does know your login info and tries logging in, Facebook will send you an email asking you to complete the final step of account reactivation by clicking a link. This email only gets sent out if someone successfully logged in using your credentials, so if you do get this email chances are someone's snooping around.
Now that you know someone's snooping, you should reactive your facebook keeping your password the same as the one used by the attackers, this will make it so they can get back in and you can now mess with them.
Now depending on your attackers, the info they look for will vary. Malicious attackers will look for anything scandalous and won't bother trying to hide there identities. They'll have messed with your profile, changed status's and whatever else they could muck up. However the more covert ones will try to not leave a trace of there ever being there, its these attackers that I'll focus on, since there actually the ones easier to catch.
The covert attackers will most likely be reading the private messages in your inbox, and usually have there heads so high up there asses to ever really think that they could be caught. Using this arrogance to your advantage is key and is what makes them so easy to catch. Just send a message to your account (from a fake account, get a TRUSTED friend to help) and the next step is to wait.
In my case I also setup an ip trap by placing links in the messages which when clicked would log the ip before redirecting to a different page. While knowing the ip alone isn't enough it usually does offer a clue as to who maybe messing with you. In my case, the ips traced back to Waterloo, Woodbridge, and the GTA, helping narrow down the number of potential attackers. But an ip alone is usually not enough to catch anyone so this is where a Barium Pill comes in handy. Simply create a dialogue between you and your trusted 'friend' and hope that the misinformation is enough to get whoever it is in your account talking to others.
Now the last step is what will really help you figure out who's in your account and how many other people may be involved. It goes without saying that most people who would snoop around your account reading your mail are probably looking for s scandal so the trick here is to create a scandal big enough. The bigger the scandal the faster most gossip queens will spread the news. Once they start talking it's only a matter of time before the rumor makes its way back to you. From there you just have to follow it back up the grape vine and boom, you have your attacker.
In my case I started the rumor that I had contracted some unknown rare terminal illness and only had a few months left to live. (Being vague worked since it made it easier to sell). It was only a matter of days before people got to talking and it turned out that it was more then just one person snooping around getting there spy game on. I continued to entertain this notion, until I started to get bored of it and that's what brings us to the final step; Ousting the attackers.
See I can't personally hate on anyone who gets there 'hack' game on, after all in my case its probably only karma, but then again I have to wonder the end game that anyone who I haven't kept in touch with for over 3 years would have to want to keep tabs on me. Then again I guess it is flattering to know that a nobody like myself is somebody enough to be followed by a bunch of public figures.
Happy April Fools Day 
