On topic, every single website that lets you upload images has that same legalese in their terms of service. Instagram, Facebook, Twitter, all of them: "by uploading your image you agree that the image belongs to us to do with it what we want and you can't complain".
"With regard to any file or content you upload to the public portions of our site, you grant [the site] a non-exclusive, royalty-free, perpetual, irrevocable worldwide license (with sublicense and assignment rights) to use, to display online and in any present or future media, to create derivative works of, to allow downloads of, and/or distribute any such file or content."