Yep, meeting them is absolutely inevitable. Some are even more convoluted then you may've initially thought. Saying they're this but really aren't but there are some that you can't entirely accuse of their alteration because they may not be aware of it either. But in a place were sarcasm fails to exist and lies muddle themselves with truth, it's almost impossible to not keep your current emotional stasis in the internet world.
I don't think anyone is under exception of it either. The whole world falls under the line of insecurity and doubt. Having no repercussions on the internet only nurtures the habitual need to be different. Depending on who you talk to, your personality may change almost immediately. It's natural instinct to reconfigure to the best of your mental ability. Even more so on a medium that masks 4 1/2 of the 5 senses.
But then again, you can see these things on a real life scale. Being two-faced is just being human. :]