If you're curious what was "deemed sufficient" you can read the court opinions from when Viacom sued YouTube/Google (and lost). [1] As I read it, the only addi

If you're curious what was "deemed sufficient" you can read the court opinions from when Viacom sued YouTube/Google (and lost). [1] As I read it, the only additional "protection" that Google was required to implement was to have a policy of banning "repeat infringers." There is some additional statutory language about accommodating "standard technical measures" that are "used by copyright owners to identify or protect copyrighted works," but as far as I can tell no such measures were identified so that didn't constrain Google in any way. [1] District Court: http://scholar.google.com/scholar_case?case=1830782936500485117 http://scholar.google.com/scholar_case?case=1830782936500485... Appeal: http://scholar.google.com/scholar_case?case=13644579048975596329 http://scholar.google.com/scholar_case?case=1364457904897559...