I think with how DMCA works, Github doesn't have to (or need to) rule one way or another. Someone sends a notice and it is taken down swiftly. If the owner thinks this was in bad faith or a mistake, they can challenge it but if you are not absolutely sure that you can win such a claim you better talk to a lawyer first.
Owner needs to send a counter-notice. Github will have to restore it. FB will be forced to take owner to court but the repo will stay up until court decides
Easy to say. But I'd be hesitant to invite a lawsuit from a company with infinite money, a predatory attitude to their users, and a proven willingness to spend arbitrary sums of money to maintain their quasi-monopoly.
Possibly. Though based on having friends who had DMCA used against them and fought it, a counter-notice immediately put the brakes on large companies.
The reason for that is simple: DMCA takedowns in large companies are handled by someone who at best is a year out of law school who processes hundreds of them per day. 99.99% of those go unchallenged because no one knows about the process. As soon as the counter-notice is served this person/entity indicates that they aren't the 99.99%, at which point someone actually starts looking at their play book. It will be another round of notice/counter notice game before someone that bills $400/h looks at the merit of a company's assertion. In the larger companies the cooler hands tend to prevail in non-obvious cases.
It is an important enough case that someone with money will probably help out. Of course, they might not, and then you're screwed.
My understanding is that Google bought YouTube mostly to avoid an underfunded YouTube in legal trouble having a bad precedent set.
If Facebook thought they could win against Google or Apple, they would have sent DMCA letters to Google and Apple for making web browsers and phone emulators with "developer tools" built in. But they know they'd lose, so they went after some random person on the Internet with no money.
Someone has to stand up to them at some point and we should support them when they do.
The fact that they're willing to just throw tons of money at lawyers to be wrong and infringe on everyone else's rights is exactly the reason we should make them take us to court on principle.