Just like in Youtube or other forums, it would be nice to have a rating on the thread or each post. When said thread gets enough negative rating or post, it automatically gets "hidden". Much like the comments section on Youtube.
It's an awesome idea, it would add great value to the site, it has overwhelming support from most everyone here, and it would make the task of discerning wheat from chaff/ signal from noise a million times easier for everyone. Your idea has been suggested here in feedback about fifty times in the past, but has never been implemented. Keep in mind that the entire feedback section was set up by Baron so that he could get tons of fantastic fresh new ideas from ET members... and then proceed to ignore nearly every single one of them, no matter how logical or popular the new suggestion may be to everyone else.