I have an account that I now visit at most once a month. I used to enjoy facebook when it was really about keeping in touch. When I joined in 2007, I really just wanted something to share pictures and stories with family and friends. Then facebook decided it wanted to become the "operating system of the web". I think that was the beginning of the end for me. Maybe many people liked this and actually (over)hyped it, but to me it made fb look more like all the previous social networks that I had (successfully) managed to avoid until then.
To me, facebook had the responsibility to handle the information you provide with care, but I believe that in their quest to become profitable, they've been quite cavalier with this notion, that is until now that viable alternatives are creeping up. I'm of the opinion that people love to know the truth, but they just don't like the lengthy process it sometimes requires to get at it, so they make judgment calls on the slightest bit of information, whether it's only a version of the truth or a partial truth. Politics is a prime example of a domain where this is usually exploited. I had an early taste of the destructive potential of facebook when I witnessed the scandal that ensued, when an acquaintance was tagged in a "compromising" photo. It was an admittedly amusing and entertaining event from my standpoint, but it prompted me to remove some of my personal information and some public pictures and set my email to warn me if someone tagged me in a picture or posted on my wall.
Then came facebook-connect, a private alternative to the public and more open OpenID. I know the latter was flawed in many ways. Call me paranoid, but I don't believe facebook was more motivated in unifying the authentication process than it was to know where its users went in the web. fb-connect imo, was an excellent trojan horse on their way to track users' habits across the web, but it wasn't perfect. Most websites still offered an alternative to people who didn't have a facebook account, to sign in with a more traditional sign-on. Also, having implemented fb-connect in the past, I distinctively remember that back then, it required the site's visitor to explicitly authorize this affiliation to take effect. Something that I've always refused to do in my effort to keep what belongs in facebook in facebook.
Then one day, after reading an article on techcrunch, I was about to post a comment and I saw the Comments box with my actual fb profile picture and name next to it. A website that I seldom visited, could now know that I was there, just because it was affiliated with facebook and I was still signed on to facebook during my visit. This new widget didn't even bother asking me if I was ok with that. That was when I started actively logging off of my fb (until then, I was just closing the window). Later on, some users started reporting that facebook actually kept tracking cookies across its affiliated sites even if they were logged off facebook. At that point, I started using a different browser just for it.
I don't understand people who don't understand why facebook get such a scorn. I like my family and my friends and I like keeping in touch with them. Just because I happen to do it with facebook doesn't mean I have to become a fan by association.