I think it's more of a problem with how they have set a bad precedent. People are in the bad habit of opening emails labeled "facebook" and clicking on links to see who's talking about them or who's pregnant or who's suddenly single or whatever.
That's exactly the problem. Immature users clicking before thinking. I personally detest websites like Myspace, facebook, and the 'social networking' type things...they are just breeding grounds for this type of malicious behavior. Sure, they can be fun and all, but many of the users are ignorant of security concerns and have HUGE targets painted on their backs to be exploited. The sites themselves are not at fault (although they could try a little harder to protect the users), rather it is the 13 or 30 year old idiot that ignores potential threats and gets wrapped up in the 'experience' of having a pic and a bio on a website and subsequently shoots themselves in the foot by being suckered into garbage like this that are ultimately at fault. User responsibility, plain and simple

O