You made this assertion before, but it's wrong and dangerous. Without knowing what the patents are, you cannot possibly say whether or not OTHER technology is infringing on it. It is especially bad considering you are not a lawyer, nor have professed any familiarity with the patent process.

It is a moderate, but known, amount of work to look through FB's patents, assess which are likely around React, and read through the claims. Considering it's possible, I certainly think that it's reasonable to ask you to do the work, or stop making the assertions.

But I have been told, by lawyers, never to read patents, because that could triple damages for knowledgeable infringement.

It also doesn't address potential patents that are still within the 18 month filing window and are still secret.

Then don't make the assertion.