There is a sense of "community" amongst regulars in online groups. It can be observed by the manner in which members of a group rally to the defense of one of their group who is in some manner assaulted. Similarly, community support can be observed when a member is troubled. Comfort, solace, advice, are offered. The bonds are reinforced via multiple means of communication (public, e-mail, IRC, ICQ).
But it seems to be conditional.
A gentleman recently made a post in a psychology newsgroup which caused me to reflect on my own experiences. The subject related to cyber relationships vs. r.w. relationships. The gentleman noted he has had many e-mail friends who have, over time, gradually stopped writing. I've experienced the same. When one ceases being an active, regular, participant in an online group, the contacts with others eventually fade away.
"Community" seems to be tenuous in cyberspace.