Don't use a FOSS license. You can still open your source, take pull requests and everything, and use a proprietary license with a clause that says the code is

Don't use a FOSS license. You can still open your source, take pull requests and everything, and use a proprietary license with a clause that says the code is not to be used for evil, where you (the author) hold the sole final judgement of what constitutes evil. Basically, copyright the shit out of your code, but selectively enforce it, and hint to the community that you are unlikely to enforce it on people who you think aren't evil. Most people will likely steer clear of your code, except for a handful of hobbyists and maybe some academics.