Really chatty people on forums might be more likely to be Es. I've noticed that like four of us in the top ten posters are ENxPs and there's an ENFJ. Not that introverts can't post a lot too...but extroverts are probably chatty and put less pre-meditated thought into their posts, so might post in higher numbers. Like having a conversation.
Some people on LiveJournal seem to do research all day long on the Internet, like don't appear to be nearly *as* social as those who would be hardcore forum addicts. I see A LOT of INxx on my friends list on LJ.
There are people who still might think I'm INFP, I don't know, but I think it's highly plausible that ENxPs, as Ne doms, would be heavily interested in Internet usage.