Well, I wouldn't even mind it if they were called just "buddies". Or acquaintances. But what kinda rubs me the wrong way is the devaluing of the word "friend".
It used to mean, as the wisecrack went, "friends help you move, good friends help you move bodies." It used to mean people you could depend on, and at the very least with whom you spent a significant amount of your time. It also did mean you need to spend some significant amount of your time just maintaining a relationship at the level of "friend".
Now apparently it means a complete stranger. It's just another row on another "mine is bigger than yours" list. Someone who, 99% of the time, you don't remember that he even exists, and he doesn't even remember that you exist, and neither would even dream of helping the other in any more significant way than a meaningless thumbs-up on a blog.
Ditto for the whole social networking idea, which takes the madness one level higher. When "friend" still meant something being a friend with a friend of X, still meant _something_. Maybe in some situation your friend would ask his friend for something on your behalf. I was reading some time ago that "friend of a friend" in mafia lingo was someone who, for example, operated a shot "family" member without asking any questions or calling the cops. But again, because the meaning of "friend" was so much more as to actually make a "friend of a friend" mean anything too.
Nowadays you have all these sites peddling the idea that you too can be only 6 degrees of separation from anyone... but it goes through 5-6 hops of complete strangers who are no more to each other than meaningless names on a "mine is bigger than yours" list. When even the first hop probably wouldn't want to have anything more to do with you than have you on a meaningless list, what is the probability that someone 6 hops away will want to have _anything_ at all to do with you by virtue of that connection? Nil. Zero. Nada.
And just to be clear, I'm not against online or virtual friends. But even then I'd expect to be someone you spend _some_ virtual time together, or hang around the same server, IRC channel, WoW guild channel, writing emails to each other every couple of days, or anything else even remotely comparable to what "friend" used to mean. Meaningless names on a list just aren't it. When both have to wonder "who the heck was JohnDoe1234 again?" that just isn't a "friend".