It especially control how easy it is to post to main. 20 karma from +1000 people is worth way more than 20 random karma.
Getting about 10 karma from introductory posts in the Welcome to LW threads wouldn't be hard. Also people can publish a draft in comment form or just ask for karma in order to write a particular article.
What do you think of the idea in general, for some other karma limit? Perhaps 500 which is probably close to what the average LWer has.
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).