> There is plenty of caselaw I can find where, for example, employees have not left, but refused to sign over patents on stuff done in spare time, and companies

> There is plenty of caselaw I can find where, for example, employees have not left, but refused to sign over patents on stuff done in spare time, and companies sued to recover them while the employee was still working there. I have yet to find one where the company lost. Is it possible to sum up briefly why this is? It seems to me that there are three kinds of spare time projects: 1. Spare time projects where the employer has no legitimate moral[1] claim of ownership. 2. Spare time projects where the legitimate moral owner is ambiguous. 3. "Spare time" projects where the legitimate owner is clearly the employer. If employers only ever bother to sue in cases 2 or 3 I'm not sure there is a problem. Especially if there are internal procedures engineers can use to secure ownership of software in category 2. Are companies routinely winning in case 1? If so this is a flaw in the legal system and should be fixed. [1] Based on current generally accepted ideas about ownership. If a developer spends his nights working on a personal project with no connection to the employer, a reasonable person would attribute ownership of his work to the developer, not the employer who pays him during the day.