Without wanting to expose someone else's anxiety, there's an interesting discussion about what it means to be a member of an online community going on in the comments at Humanities Researcher.
For the record, I suspect I do use this particular place to project myself (partly because I don't feel like I can project myself very effectively elsewhere) but I think it is a fairly harmless vanity/pressure valve. I am not getting anything from it, except for chats with nice people who otherwise I would not have met. Oh, that does sound a bit like a community after all.
The main draw back of online interactions as far as I can figure is that I can't share my banana, coconut and choc-chip minimuffins with you all. Canberra based readers, you are welcome to pop around for some.