My problem with Scribd is that anyone can violate copyright on Scribd, but only the victim (the copyright owner) has standing to report it. On their copyright page, you can submit a DMCA takedown request, but the sample notice starts with "I am the exclusive rights holder/duly authorized representative of the exclusive rights holder". What if I'm neither, but I am a random web surfer who knows that Scribd certainly shouldn't be publishing a PDF of a recent NYT bestselling book?

If any Joe has the ability to use Scribd to violate copyright, then any Jane should be able to have it taken down if she has compelling evidence it's a violation.