I can't speak to other states, but in CA the patchwork of authorities cited by local governments here have extremely tenuous legal backing to lockdown large swaths of the uninfected population and prevent them from engaging in activity that is not clearly putting anyone at risk. That is not to say such gatherings are wise, to be sure, just that the laws as they are crafted for certain limited restrictions are not sufficient to justify such wholesale lockdowns.

I can't speak to other states, but I have been reading quite a number of legal opinions that seem to take exception to those states where they are relying on these orders to justify lockdown. It will be interesting to see just how man lawsuits come from this and how many actually proceed (or, as is more likely, are settled quietly if allowed to proceed in the first place).