2. To prevent flame wars and stalkers. Nothing would be worse than good people being followed by trolls. 3. The OP asked for "who and what". 4. Isn't that what

2. To prevent flame wars and stalkers. Nothing would be worse than good people being followed by trolls. 3. The OP asked for "who and what". 4. Isn't that what happens in the comments? Best comments at the top, worst down at the bottom.