Know Your Rights:
Demonstrations & Protests
You can engage in any free speech activity, but obscenity, slander or civil disobedience could lead to arrest.
Generally, protests are protected in these public forums: streets, sidewalks and parks. Blocking traffic is allowable with a permit.
Permits may be required and the application (and potentially a fee) likely needs to be submitted several weeks ahead. Your request may be denied, but the denial cannot be based on your message. http://aclu.org/Protest