I grew up with the internet and played video games (semi-)professionally. This means that I met a metric ton of people from the internet in real life so, in many ways, became used to the idea. But check this out; not long ago, I saw a girl in class and she subsequently showed up on my "you may know..." list in FB. I added her (I add just about whomever) and it took her a while to accept. I didn't really care, and we actually ended up being really good real life friends, too!
Only later did I find out that she asked a couple of people who I was and she thought that it was (and I quote) "kind of creepy" that I added her. I'm a pretty good looking guy with a good job that goes to a great school. So why the fuck is adding someone on FB (that I happen to see in class!) creepy?
Is it any more creepy than me just walking up to someone and saying "hey, girl, put down that cellphone and have a conversation with me." Obviously not. There is something, however, that keeps us from engaging online in non-anonymous contexts due to this perceived (and I would argue Western/American) creepyness factor.
Like I said above, I'm sure someone much smarter than I will eventually figure out how to solve this very difficult problem. The solution will probably entail geolocation, semi-anonymity, and perhaps ephemeral (that is, non-persistent) IRC-like chatrooms.