how can people do these kinds of work on a speculative basis then? surely their work is protected by copyright even though if they were to reproduce it, it would be infringing. I am sure it's in their copyright when they try to sell it to the company they've derived it from.

otherwise how could anyone do spec work!

EDIT: I mean unsolicited spec work - the company they're pitching doesn't even know they're pitching them until they send their pitch. Surely their pitch is still protected by copyright, even though as it's unauthorized the person producing it wouldn't have the right to publish their pitch without approval (if it's a derivative of the company's assets)?