I would prefer that if an individual says something that causes mass chaos and real physical harm, they should be liable for it. Say what you want, by all means. But at the same time, there should be consequences for things said that go beyond the pale.
Also, genocide? Really? Wee bit hyperbolic there. The last time the US interacted with a genocide, it was to stand silently aside while the Hutus butchered the Tutsis. Even Syria hasn't descended to that point yet, though it might well be headed in that direction if things don't get any better.