The Apache patent grant and retaliation clause says that if you issue a lawsuit alleging that the licensed software infringes on a patent, then you lose your patent grant to that software.

The old Facebook license said that if you issue a patent lawsuit against Facebook, you lose the license to the software. That is in addition to the retaliation clause about the software itself.

So if you are using any OSS from Facebook, and then Facebook comes in and infringes on some unrelated patent you own, you need to stop using that software before suing or you just don't sue.