"A pile", sure, but not millions.
The "different email providers" thing is an interesting caveat, but how are you proposing to make use of that caveat in software? It's not that it's impossible on the face of it, but any software that wanted to make use of it would AFAICT have to have a painstakingly hand-crafted database of domain rules, so that you accept lots of gmail.com addresses but not lots of ciphergoth.org addresses.
The recent implementation of a -5 karma penalty for replying to comments that are at -3 or below has clearly met with some disagreement and controversy. See http://lesswrong.com/r/discussion/lw/eb9/meta_karma_for_last_30_days/7aon . However, at the same time, it seems that Eliezer's observation that trolling and related problems have over time gotten worse here may be correct. It may be that this an inevitable consequence of growth, but it may be that it can be handled or reduced with some solution or set of solutions. I'm starting this discussion thread for people to propose possible solutions. To minimize anchoring bias and related problems, I'm not going to include my ideas in this header but in a comment below. People should think about the problem before reading proposed solutions (again to minimize anchoring issues).