Earlier quoted context omitted.
Given the choice between a private dashboard vs a public repo list being spammed, I'll take the former, any day. I don't want either, but the former is an annoyance to me and only me . The latter is something that can (potentially) give a bad impression of me to others . Remember that reputation is important. Always.
I'm not sure how many times I have to say it: Adding someone as a collaborator is not publicly visible until you collaborate (make commits) on the project. At that point we show the activity on your public profile.
I got "dong markup" in my RSS reader from pull requests to zedshaw/mongrel2 today. So, the trolling was very much in public view.
So, there are ways to publicly troll someone on GitHub, even if not in this precise way.