> for [some licenses], bringing a patent lawsuit can result in termination of the copyright license as well — forcing one to stop using the code No. Copyright

> for [some licenses], bringing a patent lawsuit can result in termination of the copyright license as well — forcing one to stop using the code No. Copyright law is concerned with distributing copies and preparing derivative works. Copyright law does not give a creator the tools to forbid anyone from using their copy—that too is within the realm of patents. The way that copyright law can effectively regulate use is indirect; it prevents someone from receiving a non-infringing copy to do anything with. If you are found to violate a license (say because it's a reciprocal license and you didn't provide source code for your own changes), then even a revocation of that license can't revoke your ability to continue using the software, because that is not something regulated by US copyright law. The copy you received was prepared and distributed to you legally. Filing a patent suit, or otherwise running afoul of the license doesn't change that. There's a really pernicious cargo-culty thing going on where people keep describing a bifurcated situation, where the BSD is your "copyright license" and "PATENTS.txt" is your "patent license". BSD is a license. It deals with rights reserved for copyright holders—the right to make copies and prepare derivative works. It also deals with (one of the) rights regulated by patent law—the right to use. It grants you both. PATENTS.txt is an additional grant.