LPT: Peacefully protesting is not illegal in the US. Guess who this will be primarily used against?
That said, this is the same LRAD system that the military unequivocally promised would never be used inside the US or against civilians. The same LRAD system that failed spectacularly when field-tested in Iraq against so-called "insurgents". It's trivially defeated by any amount of metal (e.g. tinfoil hats really do work against it), rain or even high humidity, plastic sheets more than a few mils thick, wet cloth - Basically anything except bone-dry thin woven fabric is substantially effective at blocking it.
So of course, they'll just crank up the power and actually cook innocent bystanders, but let's be honest, we all know they'll do that even if it worked spectacularly well, because cruelty is the point, and 11 is more cruel than 10.
The time has come when a full-body faraday cage is required gear for any serious protestor - So naturally, we should fully expect wearing anti-static clothing to a protest to become a felony as soon as police realize their intended victims aren't squirming in pain enough to sate their sadism.