Yes, that is trolling.

Oh, I've really really wanted to do that to a couple of people. But I recognize that it is trolling so I overcome my anger. The farthest I've gone is when I see an obvious DR without substance I will find their answer on that question or their otherwise most recent answer, DR it and leave a comment.

That's exactly what trolling is. The person who flagged or dereped somebody may not have exaggerated, and the sort of punishment you're wondering about doesn't justify the means.

Yes, I've seen someone do that, but it would be "nonsense" to follow them around. "Birds of a Feather" and all that. It would definitely be "trolling."

That is a description of TWO trollers.

No, I never downrate and yes, following the downrater or the flagger around would be a form of trolling. 1) I would respect the fact that the person doing the downratings would also say it (and explain why). If they don't, you would probably have not so many clues about who did it (but the staff could find out). 2) It is not just *your* feeling. People have different views and could also have different way about using downratings. If you consider a downrating unjustified, it could not be the meaning of other people especially the site owners / staff moderators / Community Leaders (CLs). I give here my views about the use of downrating: http://www.answerbag.com/a_view/2650836 3) The best you can do about a submission, if you think it got unjustified downrating, is to uprate it. If you think that intensive trolling is taking place (a lot of unjustified downrating on a particular user or on the answers to a question), you could make a feedback to the staff and they will check it out. This would be a better and more effective way. 4) You can use the same way with unjustified flagging. However, consider that a flag does not mean a rejection, because the staff moderators or CLs are the ones who take the decision. So flagging is bad only if an unjustified flag were accepted. In this case, you could still try to reverse the flag with a feedback.