Only a court of law can determine that something is infringing. A private company cannot arbitrarily make that decision. It should be presumed that whomever uploads content has the rights to do so unless challenged by the copyright holder in a court of law. I don't care if you think it's obvious or not - that's how the law works and that's why you have to go after the uploader, not the business hosting the content.
All they're looking for is the power to say "take that website offline" and hopefully do it before any actual court ruling is made about infringing content. Once they have that power, they will abuse it to no end to make sure the only thing online are websites that meet their approval, and that power will extend way beyond the music industry. Lots of businesses will be asking to take down anything they haven't made a deal with.
In some ways we're still fighting World War II, which is really began with World War I. There is always war somewhere. It's basically longstanding political divisions trying to adjust to modern industrialized society.