Labor Law

So here's a thing -- don't have a Facebook policy at your shop. Just don't have one.
Thing is, calling someone a douche canoe is just something they could normally be fired for. BUT. And this is a giant "but". If someone writes on Facebook "My boss is a big jerk and we don't get paid well enough" and especially if someone else from your company chimes in with "Yeah" you can't fire them for that.
Why?

Because although your employees don't have 1st Amendment rights, they do have the National Labor Relations Act. And the NLRA does protect employee speech regarding wages and working conditions.
Clearly I have too much time on my hands dealing with renders today.