Kendo - 12:41 am on Apr 28, 2013 (gmt 0)
By that definition there is no good DRM.
But there is. I can show you documents, images and video that can be displayed online or distributed on disk that cannot be decrypted and the DRM cannot be removed.
Just because psuedo protection* may have been exploited, it does not mean that everything can. A lot of DRM and copy protection that has been out there if anything, has been designed by scammers or designed to be too user friendly or to be supported on too many different OS and devices, including devices and OS incapable of being properly secured thus undermining security policy and providing weaknesses for exploit.
I fact I can send you a file that only you can open on one computer (or 3 if I allow it) that you can send to 1,000s of friends and not one of them will be able to open it. And that file cannot be decrypted. The only way that you can copy its contents is by photographing your computer screen while it is open on you computer, the only computer approved for access.
* protection is related to experience and while some solutions cannot be cracked even by the most experienced, the effectiveness of protection can be awe inspiring to the naive as I once discovered when discussing right mouse click scripts online. One user was so impressed by this new knowledge that they ran off with what they thought was the most amazing and most effective copy protection idea to market it is a product (of their own design).
Of course this person was naive, but the example may server to explain why there is so much useless DRM and non-protective copy protection out there.