Like many others here, the couple times I've been along from start to exit, despite all the contracts and promises and hard work at low pay with no overtime, key contributions, etc, so far, never a dollar, and in one case, a protracted legal battle as they tried to steal my preexisting IP which I had a signed agreement from them acknowledging belonging to me, signed before I started work.
What kind of loophole in your signed agreement did they try to use to get hold of your IP? Was there a problem with the contract, or were they simply hoping you would cave in order to avoid a legal battle?
I had things locked down great, as I had gone to work with them to implement my IP that they required fundamentally as part of their business. They signed a licensing agreement and a document outlining the various inventions I had coming in to it. After their product was ready to ship, there was a buy out offer, but required exclusive ownership of my IP. The license was non-transferable and required renegotiation. They didn't like this and asked me to transfer ownership outright to them for free or they would fire me and I would lose all my equity. They had absolutely no case whatsoever, but this didn't stop them from launching legal proceedings against me. These went no where since it was only for the purpose of strongarming and intimidating me. At one point, a vice president of the company was telephoning relatives of mine and threatening them if I didn't cave. I didn't cave, held to my position (which was very reasonable), and they didn't bother to proceed since they knew they had no case, but only after tens of thousands of dollars in legal fees to top notch lawyers to represent me against them. Several months after this they sold to another company (Fortune 500 sort) and lied to them that they owned my IP, not mentioning me at all. That company then patented it, with the VP claiming to have invented it. At the same time I have his signature on a licensing agreement, the exact text describing the invention which appears on their new patent, granted some 10 years after I first implemented it. (It was previously a trade secret that I was selectively licensing.) Of course the next question is why don't I sue them. That's easy. At the end of all this I was broke and in debt and there's no lawyer taking IP cases pro bono. They are tremendously expensive and in the end the company with the deeper pockets nearly always wins. Good IP lawyers run $400+ per hour.