Some scam applications have recently appeared on Facebook. They can cause lots of harm, so if you see these on your feed, do not click on them.
The among the latst latest is the so-called "my first status" scam. If you click on the app, it is supposed to generate your first status update, I'm assuming for those of us who might wax nostalgic over their social networking activities. What will this app do? If you give it access to your profile, you will be sending the same link to your friends. And then, says network security company Sophos, comes the survey: "This is where the scammers behind the scheme make their money. Every survey which is completed earns them some commission. In some cases they might also ask for your mobile phone number in order to sign you up for an expensive premium-rate service."
Other scams include the worm that spreads in Facebook picture chat sessions, and the Suge Knight/Tupac Shakur scam. Apps like these are nuissances in the best case, and major security problems at their worst.
I don't use a lot of apps. Others put more trust in them. But these apps are more reasons to be cautious when using facebook.