Who cares how old people on t'interweb are. If you're that interested in them, meet them in real life and you'll find out.
As for the title of this thread, chatrooms, forums etc have the advantage that you can do what you like without fear of nasty things happening - at worst, you'll piss off some total strangers who live hundreds or thousands of miles away from you. They're a sanitised environment, removed from some of the complexities of 'live' social interaction.
They have the disadvantage that you can't see the other person's face or body language, which is mostly how we tell how others are feeling, and there's no safeguard against lying. saintnick, for example, is obviously taking the piss, but there are lots of people who have a completely different personality on the internet to face-to-face, and often it's not even deliberately so. For example, I'm not nearly so verbose in day-to-day conversation.