Edit: I see one fellow saying to have a lawyer send a C&D or some other sort of nastygram. I agree that's premature, although if he asked a lawyer to do that t

Edit: I see one fellow saying to have a lawyer send a C&D or some other sort of nastygram. I agree that's premature, although if he asked a lawyer to do that they'd most likely inform him about other options. On first read, I think this is very, very bad advice. It depends on what you mean by "lawyering up," but all I see are other commenters telling the OP to talk to a lawyer. He should 100%, absolutely, without question talk to a lawyer — if for no other reason than to understand his options and their legal consequences. At an absolute minimum, he should have an attorney read over the invention assignment agreement. Beyond that, he has three choices WRT the agreement: sign it as is, sign a modified version of it, or sign no version of it at all. A lawyer is the only person who can honestly talk to the OP through the legal consequences of each choice. For example, if he doesn't sign, what rights do the other founders have? What rights could they reasonably claim? Is he liable for anything? If he decides to use some or all of the software or other assets he developed while working on this project with these other people, could they have any kind of claim against him? This is basic diligence and doesn't mean he needs to be aggressive, sabotage the project, get them kicked out of the accelerator, or anything else.