So I checked StackExchange's law site and found this question - thus far unanswered, but those would be my questions exactly: http://law.stackexchange.com/questions/14337/q-about-consequ... It comes down to two questions (quoted from the linked question) - note that those are questions , not assertions: 1) > ... if we use any of Facebook's open source projects Facebook can violate *our patents* (of any > kind) pretty…
2) The patent grants from Microsoft and Google grant a license on software (or a standard), and only give them a (reciprocal) license on the software or standard that is under consideration. If Microsoft had published React, you could still sue them for violating patents that are unrelated to React without losing your license to use it. The Facebook grant doesn't have this, so if you rely on React you can't sue Facebook at all. But they can still sue you.