Earlier quoted context omitted.
The clause states you only lose the patent rights if YOU sue Facebook for patent infringement (and only for patent infringement, not other reasons). As pointed out by Dennis Walsh in ( https://medium.com/@dwalsh.sdlr/react-facebook-and-the-revok... ), it would take millions to bring a patent suit against Facebook.
Yeah, and if Facebook DOES infringe on a patent you own, and it's a valid case? You then have to rewrite your frontend code base as fast as you can? At it's best this is like some sort of warped "you infringe on my patents and I'll infringe on yours" kind of thing, assuming MAD means it doesn't become a very-uneven suing war. This case is also bad news, because larger companies are much more capable of infringing on…
In that case, you have two other options:
* Quietly swap out your frontend before you file
* Continue using React and dare Facebook to produce a patent they can actually claim
This, of course, is based on the assumption that your frontend is a significant portion of your product. If your frontend is a trivial portion, then "rewrite your frontend code base as fast as you can" is also trivial.
Edit: fixed formatting