I generally agree that heavily moderating a subreddit is a bad idea, however for subreddits like http://www.reddit.com/r/science http://www.reddit.com/r/science

I generally agree that heavily moderating a subreddit is a bad idea, however for subreddits like http://www.reddit.com/r/science http://www.reddit.com/r/science and http://www.reddit.com/r/askscience http://www.reddit.com/r/askscience, they have been able to scale up to frontpage levels without a serious drop in content quality.