If you post things you don't have the intellectual property to, you often will get a cease and desist letter or, if the person reports it to the service (like YouTube or Facebook) then the service will take it down.

So as a choreographer if someone posts my work and I didn't give them permission, I can report it and have it taken down or I can send a cease and desist letter. It's no different than taking a photograph you don't own and posting it. Technically you aren't allowed to.

I am not sure how an anonymous posting would go, but it could damage the chances for a film festival. That's why they often don't share the footage until they are ready to release it. I'm not sure the deal with the producer sharing it to YouTube or whatever. It's one thing if you find a link and share a link, because you are linking to the original source. But to repost as your own is highly frowned upon.

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