YouTube's recent successful defence of ViaCom's claim for massive copyright infringment has been appealed by ViaCom and the outcome will draw a clearer line as to the how much effort a platform like YouTube must make to escape liability.
US District Judge Louis Stanton felt that the DCMA Safe Harbour provisions applied to YouTube because the view was taken that specific knowledge of infringement was required - not a general awareness that content may infringe.
By implication ViaCom needed to make more effort to notify YouTube of specific infringement.
Cases such as LimeWire and Grokster show that the content owners can defend themselves - but need to follow best practice to be successful.
The FA Premier League are also linked to this action and it would appear were not successful in the first instance because takedown procedures were not complied with and also copyrights were not registered with the US Library of Congress.