As of 2015, there is no definitive legal answer as to whether watching full episodes of TV shows on YouTube is illegal, according to FindLaw. However, those who post TV episodes to YouTube are violating the copyright of the episode and are breaking the law in doing so.
Violating the copyright of a TV show is a misdemeanor in the United States, and is punishable by a fine or jail time, explains FindLaw. In 2008, there was an attempt to punish individuals simply for viewing an illegal television episode on YouTube, based on the fact that the site makes a temporary copy of the video on the computer during streaming, according to an article published by CNET. However, there were no reports of an individual actually being issued a fine under this policy.