If service providers wanted to take down e.g. HN, such a pretext would be easy enough to create. HN would never get to that point, however, since most posts here don't piss off "protected groups". From my brief perusal in the week that I've been aware of KF, nearly every thread was intended to piss off such a group. That's a widely appealing if thankless task, so alternatives will probably be created soon enough.