There must be some sort of limits to what's protected though, right? SpaceX said they were fired for sending company-wide emails badgering people to sign stuff, and I'd have to imagine there's some line when it comes to using company time/resources to organize. If you grab a megaphone and start disrupting a whole factory floor by using it to try to get people to organize for better rights while you're supposed to be working, that seems like it ought to be a fireable offense, where organizing at someone's house outside of working hours clearly should not.