Grabbing rootkit artifacts that could be on the device?

Its just that its not Facebooks place to do this. I wouldn't expect a app linux binary to upload the contents of /usr/lib, or a windows app to start sending system32 dll's off system.

FB can try to sell this as a 'lite-AntiVirus' type service, but that is not its place. There is no indication the app is doing this. Its FB being creepy as usual.

If Google did it, it would be less creepy, just like how Microsoft can grab malicious files detected by Defender -- but they write, support and protect the OS! FB is just an app. It shouldn't be harvesting its users operating system files!