Any person who knowingly materially misrepresents under this section
(1) that material or activity is infringing,
(2) that material or activity was removed or disabled by mistake or misidentification,
shall be liable for any damages, including costs and attorneys' fees, incurred by the alleged infringer, by any copyright owner or copyright owner's authorized licensee, or by a service provider, who is injured by such misrepresentation, as the result of the service provider relying upon such misrepresentation in removing or disabling access to the material or activity claimed to be infringing, or in replacing the removed material or ceasing to disable access to it."According to the US District Court for the Northern District of California this means you have to do some due dilligence and apply some common sense before you fire off the takedown notice, lest you violate the "fair use" part of US copyright law. I would not be surprised if this (or a similar case) does not get appealed the US Supreme Court because I'm sure that the lawyers won't accept "use common sense" as a valid instruction unless the US SC orders them to stop being so idiotic and nitpicky.