Facebook filled a gap: it let me keep abreast of people who don't blog or to whom I am not close enough to want to share detailed blog entries. It's the best way for me to keep up with my many former colleagues, and its telegraphic style makes it possible to actively watch a very long friends list.
Or, it used to. Facebook has gotten increasingly problematic. Even though I have set my preferences to the contrary, my news feed is filling up with so much spam and crap that I miss significant updates (like new photos) by friends from whom I really want to see updates. I turned off email notifications because the vast majority of them were notes not from friends, but from applications my friends had installed. I mostly ignore those requests, but I was becoming increasingly puzzled by the amount of spam I was getting. Had all of my otherwise rational friends suddenly turned into junk-mail-forwarders?
I decided to accept a few requests and see what was going on. I went through eleven screens to read a one-line Christmas card message from one person, tried to return a thrown snowball to someone else (and after ten or twelve screens gave up entirely), and tried to share music through iLike. None of these applications worked properly, and all of them did their best to trick me into spamming everyone in sight. I've documented my interaction with one particularly deceptive application below, but this is pretty much standard behavior for most third-party Facebook applications. It is very difficult to install these applications without spamming your friends; they mislead or tell outright lies in order to get you to do so, and in this case, even ignoring it entirely won't help.
So, to my Facebook friends, it's not that I don't appreciate your sending me gifts and cards and attacking me with your werewolf. I'm up for a snowball fight anytime you want to come over (assuming we get some snow). But I won't be accepting any more of these invitations.