sentences:  Microsoft later claimed that the paper contained various factual errors.While great care had been taken with AACS to ensure that content was encrypted along the entire path from the disc to the display device, it was discovered in July 2006 that a perfect copy of any still frame from a film could be captured from certain Blu-ray and HD DVD software players by using the Print Screen function of the Windows operating system.It was suggested that this approach could be automated to allow a perfect copy of an entire film to be made, in much the same way that DVD films were copied before the CSS was cracked, but to date no such copy has been discovered.