Remaining silent on patents is better than issuing an unfair and one-sided patent license.
If Facebook doesn't intend to assert its patents aggressively, why does it want to prevent users of React from defending themselves?
If Facebook doesn't intend to assert its patents aggressively, why does it want to prevent users of React from defending themselves?
Granting patents in the context of permissively licensed open source is a generous act and making the grant conditional is a way of not giving up your ability to form the strongest possible defense when you're brought into patent litigation. If you have been following along the recent years events (where is that patent apocalypse, anyone?) then it should be no surprise why companies need to do that.
Conditional patent grants are not new. Apache License v2.0 has a conditional patent grant [http://www.apache.org/licenses/LICENSE-2.0]. Google added a conditional patent grant to WebM, complementing its Modified BSD license [http://www.webmproject.org/license/additional/]. Google's Dart project is licensed under Modified BSD and has a.. you guessed it - conditional patent grant [https://code.google.com/p/dart/source/browse/trunk/dart/PATE...].
Apache, GPL, MPL, etc. have retaliation clauses that terminate your patent license only if you sue (or in some cases, countersue) in relation to the covered software. Facebook's patent grant says you can never sue Facebook, while being vulnerable to being sued by Facebook for anything but React.
Edited for clarity.
But I'm not sure I agree with your conclusion though.
Scenario one: MYCOMP uses React in a product, decides to sue FB because FB uses the term "It's complicated" which MYCOMP was granted a patent for by the US patent office (the phrase was translated into a dual-ROT13-machine for the purpose of the patent application). MYCOMP had tried to get FB to pay them a reasonable license fee prior to suing but Facebook neglected. Now MYCOMP does not have a patent grant for their use of React any longer but isn't that then ~similar to as if React didn't have any patent grant to begin with (from a litigation perspective) - like most MIT and BSD licensed software we use? Had I been with BIGCORP I'd have asked the legal folks or our favorite patent attorney but now I'm solo so I'm throwing out the question here for further discussion.
Scenario two: FB sues UCOMP (who uses React in one of their products) for patent infringement of FB's "Send message from client to server" patent (nicely masqueraded in the patent application). UCOMP decides to counter-sue and we have a situation similar to scenario one.