> My understanding is a patent holder must defend their rights, if they are aware of the infringement, at the peril of losing them.

Pretty sure that's just for trademarks.

Agh. Absolutely. Wrong flavor of "intellectual property". Thanks.

And that's why Stallman is so firm that there is no such thing as "intellectual property". As soon as you start using that term, you start believing there is something more general and meaningful to it and start muddying the concepts. But it is just a mirage.

https://www.gnu.org/philosophy/not-ipr.en.html

You lose a trademark if you don't defend it. I don't believe the same is true of patents.

My face is red. Thanks. I didn't stop and think long enough before I posted.