Unfortunately, there are many ways to lose control of your Facebook account. Simple click-jacking attacks can hijack your "Like" ability, driving up stats for specific pages. That's not so bad, but you can also get hit by innovative malware that resides totally on Facebook. With no software installed on your local system, there's nothing for your local antivirus to detect, and your account can be hacked in a jiffy, leading to all sorts of hassle and problems.
Every time you take a quiz, install a Facebook game, or add any app, you get a screen specifying what permissions the app needs. These permissions can include almost anything up to and including accessing your Facebook account even when you're not logged in.
If you don't read these carefully you can wind up giving away your personal information – so scrutinise them!
Also be wary of videos on Facebook. Sometimes when you launch a video you get a notification that a new or updated codec is required before you can view the clip. This might be true, but quite often the so-called codec is actually a Trojan. An antivirus program should block this one, though (should being the operative word, however, so again exercise caution – if it looks even remotely suspicious, just leave it well alone).
Norton Safe Web for Facebook is bundled with the Norton security products, but anybody can use it for free. It scans your Facebook page's links and reports any bad ones. BitDefender SafeGo for Facebook rates your profile privacy and checks for dangerous links. If you're concerned about dangerous links (and you should be), installing one of these can definitely help.
Facebook keeps working on security internally, but they can't stop you from giving away your personal information in order to play a game or take a quiz. A local antivirus won't prevent that mistake either. In the end it's up to you – pay attention, and if an app asks for too much information just don't install it. Also, an extra layer of social media protection such as Norton Safe Web doesn’t hurt.
You might also want to check out our security tips for social media sites.