Piracy as a growth strategy was very common at the time. Everyone, including Youtube, was just rushing to stay on top long enough to translate piracy into money sufficient to keep the lawyers away a few days longer.
>> Karim left YouTube before Google bought it in 2006. But he kept YouTube e-mail on his personal computer, enabling Viacom to obtain correspondence that Hurley had said he lost, according to court documents. [..] In a July 29, 2005 e-mail, Chen advised Hurley and Karim to "steal it!" in an apparent reference to an unidentified video clip, according to the court documents. After Hurley asked if he wanted to steal movies, Chen replied, "haha ya. Or something."
>> Google had its own copyright reservations about YouTube before it struck a deal. Internal documents obtained by Viacom quote Google executives describing YouTube as "a 'rogue enabler' of content theft" and warning the site "is completely sustained by pirated content."
https://www.cbc.ca/news/science/youtube-viacom-spat-gets-dir...