In the early days of music streaming, many of the entrants were seeding their service with vast libraries of pirated content. The winners cut deals with the copyright holders and then went after the rest.
Viacom sued YouTube, while CBS and Universal ended up licensing their content.
https://www.eff.org/deeplinks/2007/03/viacom-v-google-invest...
Facebook et al also quite literally stole email contact lists and installed spyware at kernel level on mobile phones which they used to spy on all Android users. Via the phone manufacturers.