I don't know much about ScribD so let's start with that; consider me ignorant. I assume it's some sort of hosting site for ebooks, correct me if I'm wrong.
But, is it possible to sue them? The Pirate Bay is constantly threatened by law suits (and they're actively supporting piracy) but they seem to escape certain copyright laws by merely acting as a host site for other pirates. Now, the people uploading music and movies and games COULD be sued, but not the website's staff.
I'm a bit rusty on this, and my knowledge may be out of date, but for what it's worth:
The "merely acting as a host site" bit is referring to Common Carrier Law. This is the law that prevents a phone company from being liable for phone calls associated a crime, or gmail from being liable for e-mails associated with a crime. We don't WANT the phone company policing phone calls, or an e-mail host policing e-mails.
There was quite a bit of argument a few years back (it may still be going on) about who, in the world of the internet, has "common carrier" status (and thus is not liable for things their service is used for) and who does not have "common carrier" status (and is thus liable.)
Last time I was paying attention, there were quite a few lawsuits going on over whether hosting sites had Common Carrier status or not. While the general consensus seemed to be moving towards "not" (hence, for instance, the original Napster being shut down), I'm not aware of the current legal status -- and having more than one country involved will always complicate things.