Legal for 3rd party file hosting service to host copyrighted materials?

For example, commercial ebooks and electronic version of Amazon books?

Does the copyright owners fire complaints to those services? My assumption is that they DO but does the hosting service providers have to remove the resource? Is it against the law if they don't? They must have some kind of disclaimer, but does this really disclaim them of the possible infringement of hosting these copyrighted materials?

I know a lot of forums where members share with each other copyrighted ebooks, in this case, will the forum owner be caught in law?

 

I think this also falls on the file host......I know a couple of file hosts that were contacted directly by the copywriter.

 

Yes, they do complain. It isn't legal. Example: http://www.webhostingtalk.com/showthread.php?t=648277