Ask HN: Facebook's Open Source Policy

From the talented folks here. I want help in understanding and testing out Facebook's open source policy.

First the understanding part. The Facebook's patent grant seems worse than GPL (because you can't even link to it and they can revoke it retroactively by forcing you into a lawsuit). Facebook as a company has no qualms in blatantly copying anyone they like. Facebook has the resources to enter any software market. They have been creating more and more infrastructural open source pieces (we always need to double check if the node module we use hasn't been tainted by a facebook dependency).Very few people seem to question the intents. Why is world not paranoid? Yarn seems like Embrace, Extend, Extinguish. Can folks explain why this is not? I have seen lots of M$ haters but haven't seen many F? haters.

For the testing part. Can someone create a versioned list of FB projects with no patents in them or help create patent free forks. They have made it difficult to know if a project actually has a patent. They can't revoke a patent right if there is no patent to revoke. I would love if HN could discuss and email the authorities the prior art in all these patents when they are filed and cleanup the garbage before it gets thrown into open source. I don't know how this would work if say a project that FB depends on creates a licensing argument like this(open it up for all lawsuits against the present and future sponsors of the open source project). It would be great to know whether facebook is willing to bite what it wants us to chew.