Thing to realize is that a lot of these people on forums who won't accept feedback, enjoy 'flaming' others and such are all punk teens. It's in their nature to fight back without rationally thinking about what people are saying just for the simple purpose of gaining independence in both thought and opinion. It's a matter of matturity and everybody went through it. Just have to keep that in mind and not get pulled down to their (natural) level.

If they're not teenage rebels then their either not completely balanced in their lives or stupid. Either way you're above them.