I will never use React for anything but (possibly) toy projects. You don't need a lawyer to tell you being unable to sue Facebook for patent infringement even

I will never use React for anything but (possibly) toy projects. You don't need a lawyer to tell you being unable to sue Facebook for patent infringement even if unrelated to the licensed software, while Facebook is free to sue you for infringing other patents without you being able to challenge such patents, is an unfair and dangerous license. And counting on Facebook's good will is as foolish as betting your livelihood on a Microsoft "promise" not to sue you. Edit: fixed typo.