Typical social restraints just don't exist online, for most people. People will loudly mock viewpoints counter to their own using all sorts of insults, and these comments are broadcast to every friend they have. I can't even imagine one of my friends standing up in the middle of a party, and announcing to the room how disgusting they found "social_group_x" or how criminally insane are members of "political_group_y." And yet they regularly do exactly that online.

When you talk to someone in person, you're careful about what you say. You don't lie or hide your opinions, but you try to couch things in friendly terms, avoid causing offense, etc. For whatever reason, people are just unable to translate those niceties to the online space. Consequently, my friends list is very small, I've hidden lots of people from my wall, and I virtually never post anything myself.

RAFOnauts: be careful with your online opinions. You're annoying/offending a lot of people who like you enough not to start a fight.