Pirated video streams of televised National Football League games are widespread on Facebook and on Google's YouTube service, CNBC has found. From a report: Using technology from these internet giants, thousands of football fans were able to watch long segments of many contests free of charge during the league's Week 13 schedule of games last Thursday and Sunday. Dozens of these video streams, pirated from CBS and NBC broadcasts, featured ads from well-known national brands interspersed with game action. This online activity comes as the league struggles with declining ratings that have been blamed variously on player protests during the national anthem and revelations about former players suffering from a brain disease caused by concussions. Yet this illegal distribution of NFL content may also be crimping the league's viewer numbers.