Depends on the person. If the person criticizing me is someone who has proven themselves to be a thinker and reasonable person, I’ll them and their criticism seriously. If the person is a known and proven asshole, I’ll either completely ignore the person or do some sort of a retort that puts the issue back on them and shows their assholeishness. If it is someone totally new with no history, I usually won’t respond until the person has proven himself one way or another.