I deflect 100s of garbage submissions by automated tools daily straight into a junk submission log file just so I can see who's attempting the auto junk. The auto submitters do stupid things like attempting to include HTML, raw URI's in field locations other than the URI field, invalid browser user agents, so on and so forth.
In the rare event something might slip past, especially one done by hand, I have positive filters that look for the types of things people normally post and anything that skews the norm is thrown directly into moderation for manual review.
I run a site designed to be used by people, submitted by people, it's a B2C type of thing so there's no room for junk otherwise the whole thing falls apart.
Rarely do I rewrite submissions unless it's for a paid advertiser, not to brag, but the ads I rewrite get a lot of quality traffic :)
It just baffles my mind that someone can't describe what their business does in 250-500 characters or less.
How could these same people run an effective AdWords campaign?
Maybe I'll do like FaceBook's ad page does and put up examples so they can see what's expected.