Personally, i find myself in being MUCH more outgoing when behind a monitor. I'm shy and a bit socially awkward in real life, and while the awkwardness might still remain, the shyness vanishes on the internet. Probably because there is a vast difference between looking at an avatar plus some written text and looking at someones face and hearing what they're saying. On the internet, it's dead easy to hide emotions, and you have all the time in the world to ponder your next move, but when talking to someone, you can't just mask your emotions like that, because people generally expect a reply from you pretty quickly.
So yeah, long story short, if you removed all shyness from my real personality, you'd have an almost perfect match on my internet personality.