It is juvenile, but it happens. The Slashdot folks designed a system of moderation whereby users can 'vote' on the quality of comments that others have left. So when a fair number of people have commented on others' comments, you have in a sense a 'popularity contest' for the quality of postings. Slashdot receives thousands of postings a day and so needed to figure out a way to make sure the cream always rises to the top. That's why they developed the moderation system.
Readers can then set the quality level of posting they want to read.
When moderators are given access, they are given a number of points of influence to play with. Each comment they moderate deducts a point. When they run out of points, they are done serving until next time it is their turn. Bad words will reduce the comment's score by a single point, and good words increase a comment's score by a single point. All comments are scored on an absolute scale from -1 to 5.