Would it be possible for us to have an event kind that can't be rebroadcasted by anyone except the original transaction signer?

Let's say I'm a content creator and publish my event to my paid and private relay. Any of my paid subscribers can just rebroadcast the event to any other relay. This is great for decentralization and allows notes and events to live on, however this scenario wouldn't work for paid content.

If we had a special event to flag as relay specific content that cannot be rebroadcasted without being resigned by the original signer, that would solve this. Correct?

Thoughts?