This is exactly like the broadly misunderstood TOS for Facebook, Etsy and other services. They need a license to your work in order to distribute it, and display it to others or perhaps even you. These clauses have been in TOSs for years and years, and only now people have taken notice. The average person doesn't know much about IP though, and probably couldn't tell you the difference between a copyright and a patent…
Just because it is standard doesn't mean it is acceptable.
If service providers didn't secure a license from the uploader/creator of a work, this could happen:
- Jim McJones uploads his photo to flickr
- flickr displays his image to the public
- Jim McJones sends flickr a cease and desist or sues for copyright infringement
Which leads to... huh? Obviously the intent when you upload a photo to flickr is to have them display it for you. But they need a license, and since this is a legal issue, it needs to be written in a legally specific way. Thus, that's what everyone has done.DropBox's clause relating to this was already decent and fair in my opinion. Of course, I am not a lawyer or legal expert, just someone who both creates content and runs websites which distribute other peoples' works.