I thought this was against the rules...I was told that or somehow got that impression like 2 years ago at least. It's like polygamy. Except not at all.
I'm a member of a teamspeak community (you have to sign up first to be able to connect to the teamspeak and do stuff).
I also tried my hand at making a clan, the actual clan part fell through but we are still a community (search Clan NaGa).
I keep in touch with my old clan buddies, but I really haven't talked with them or anything in a while. Plus, there hasn't been any activity on their website in ages.