It doesn't matter what Rapidshare want
They have absolutely no way of preventing a general file upload / download service being used for piracy.
They could scan file names and pirates would pick random ones.
They could look for audio / video data matching particular fingerprints and pirates will just zip up the content.
They could unzip the content to scan it and pirates would simply encrypt the content with a strong password which they disclose elsewhere such as on a forum.
They could ban encrypted zips but then pirates will start throwing data into other seemingly innocuous container formats.
They could monitor referrer links but pirates would start redirecting download links through seemingly innocuous thirdparty sites.
They could monitor downloader's IP addresses at which point they start using Tor or other anonymizing services.
It's an arms race. There is absolutely no way Rapidshare can police or prevent all but the crudest forms of piracy. They can include a "report this link", they can flag content which is suspicious, they can facilitate legitimate takedown notices but there isn't much else they could do without annoying their legit customers or hurting their own service.
I wonder if the answer isn't to know more about the data but to know less. To require all uploads to be encrypted and to give all uploads incomprehensible names. Then they can respond to takedowns as they come in but they are not in a position of having to police the content because they have no idea what it is. They're basically carriers.