Justified: In the real world, if you constantly become a Jerkass it becomes a permanent Never Live It Down that can ruin your reputation forever, thus acting as a Restraining Bolt. Having low visibility and no identity thus allows for people to express their repressed aggression without the social consequences.
Anonymous people are the nicest folks you can hang around with while the named ones are the narcissistic jerkasses.
Alternatively, The Anonymous person is just as polite behind a computer screen as (s)he is face-to-face in Real Life.
Enforced: The author wants to show what humanity would really be like if there wasn't a Big Brother to keep them in line.
Lampshaded: "Just because you have no name, you already act retarded?"
Invoked: In order to Prove that Bob has a dark side, she sits him in front of a chat site occupied entirely by wickedly skilled trolls.
Exploited: Alice is secretly logging every embarrassing thing Bob says on the internet without him knowing and is planning to blackmail him with it later when he wants to maintain a wholesome image in person.
Defied: When Bob goes to the Internet, he takes precaution to restrain his behaviour and be polite to anyone.
Discussed: "We must be cautious when we go to the Internet. You wouldn't like it if your life was damaged forever by unseen forces just because you poked this guy."
Conversed: "You know, I don't think Fred would be able to say that to Wilma's face..."
The anonymous person is a paranoid shut-in who lives in a gated house with several angry guard dogs out front; a sign located just at the edge of the property warns that any trespassers will be shot. Anyone who manages to track this person down takes one look and makes the very wise choice to let bygones be bygones.
Back to GIFT, dickhead! Are you upset, sissy pants? What do intent to do about it, tough guy?! Are you gonna punch me!? HA HA HA! Loser, I want to see you trying it.