So the more reasonable thing is to block mentally instead of letting the computer do it?
The problem with people who you'd want to block is that a good amount of the time they say something that gets you to think things through in a different light. It sucks to get flamed, but boy is it a good tool to force a reassessment of what you've said. Sometimes you realize you were dead right, and sometimes you realize the guy you want to block has a good point.