Dont confuse free speech issues with that which you find "disturbing".
If someone is WILLFULLY disturbing your peace, no matter what time of day or where, they can be arrested, if; the offense is committed in the presence of the police, or if the police are not there, via citizens arrest (837PC in Cali). Once a citizens arrest is made, its a felony for the police to refuse to take your prisoner.
Otherwise the police stay away from free speech issues for 1 reason, on duty cops cant legally be offended by ANY speech... you can call a white guy a nazi, or tease anyone about their race on top of insulting their momma, sister, wife... whatever. As long as its not a threat, cops have no official opinion and cannot have their peace disturbed while on duty.
Thats why I advocate "mob justice" for these people, a mob needs to open a can of punk-rock whoopass and summarily beat them down to shut them up.
Even the biggest loudmouth on the planet cant talk with a boot in his, or her mouth.