Anyone know which are the patents in question? Reactjs was released in 2013. I just did a quick search for a few plausible keywords on Google Scholar, and it revealed nothing. It would be nice if Facebook would come clean as to which of the patents that they would claim cover React.
Its not just patents in React. Its patents in "any software, technology, product or service of Facebook or any of its subsidiaries or corporate affiliates" https://github.com/facebook/react/blob/master/PATENTS
First, there is the set of patents that Facebook is licensing to you.
I'll call this set "the React patents".
Second, there is the set of patents that someone might sue Facebook over, alleging that Facebook has infringed. If you are involved in such a suit you lose your license to the React patents.
Third, there is the set of patents that someone might sue someone else over, alleging infringement, and for which that alleged infringement arose at least partially from "any software, technology, product or service of Facebook or any of its subsidiaries or corporate affiliates". If you are involved in such a suit you lose your license to the React patents.
I'll call the union of the second and third sets "the triggering patents", because suing over them can trigger loss of of your license to the React patents.
The part you quote is referring to patents in that third set, which are triggering patents, not React patents.
Facebook has stated that termination of the patent license does NOT terminate your copyright license [1].
The question grizzles asked about what Facebook patents cover React is interesting and important because if it turns out that the React patent set is empty then you don't actually need a React patent license from Facebook. All you need in that case is the copyright license.
I've not heard of anyone finding any React patents, but that doesn't mean there could not be some applications pending from Facebook that would cover React. It used to be that a good patent attorney or agent could keep a patent application delayed and secret a very long time so that there was no way in general to tell if something was safe.
I vaguely recall that there were changes to US patent law that made that a lot harder, but I'm not sure if they completely made it impossible, so I'm not sure that we can ever be sure that we don't actually need the patent license.