i'd be very surprised if it is technically legal. copyright is copyright. and infringement is infringement. unless the website is paying fees to the entity owning the rights, its likely infringement. but, like a lot of these things over the years, there is probably very little risk until you start distributing it yourself. remember the federal prosecutions over some of the sites like napster and the like in the early 2000s maybe. there were some users that got slapped with hundreds of thousands of dollars in fines if i recall and they held up under appeal. but, in that situation, users were also distributing as that is how the platforms worked. once you had downloaded to your computer, the site also pulled the download from you to distribute to others. so, apples to oranges. but, again.... i would be surprised if these websites are legal