I agree. The quality of some of the content on Trending is pretty poor. Some even looks to be bot-generated. I see users reposting lots of content that's not theirs (repost of YouTube vides etc).

I've had a poke around the content of the block chain and it should be possible to write something like an ad-blocker to black list bot-users.

I think the answer is human curation of content with something like @steamfollower. While not perfect, it's not quite, buying votes