It really is time for copyright reform. It's stupid that a site like this (or like the YouTube of old) is essentially untouchable (under the DMCA) despite not even trying to prevent people from uploading copyrighted material; it's also stupid that some random pirate can get ordered to pay millions of dollars. Maybe a standard penalty of ~$10/infringement (scaled by cost of original), with minimal hassle, would be the way to go.
And, while we're legislating copyright reform, let's throw in a requirement to store the hashes (or other identifying features) of any content that has a DMCA filed against it and check all new content against that list of hashes to prevent infringing content from being uploaded again.
Of course, then there's the problem of people using fake DMCAs to get content removed (which does happen). Allowing profit for that would be a horrible idea, especially on a scale low enough that it would be cheaper to pay than to verify that the person who filed the DMCA does indeed own the copyright.
Yeah. Other identifying features, then - I'm sure that someone has come up with a way to identify images which ignores such basic changes to them, especially considering what TinEye does.