Every big service has to honor DMCA takedown requests. In fact, every service in the US needs to honor them lest they want to become a party in a lawsuit for copyright infringement.
Most of them are far more aggressive about taking things down than the DMCA requires and they also don't allow counter-claims that would be allowed if they were actually following the DMCA. If it was just a DMCA takedown request, then the uploader would basically just have to say that it's not copyright infringement and then the only recourse for the takedown requester would be to take the uploader to court.