“The mere tendency of speech to encourage unlawful acts is not a sufficient reason for banning it. First Amendment freedoms are most in danger when the government seeks to control thought or to justify its laws for that impermissible end. The right to think is the beginning of freedom, and speech must be protected from the government because speech is the beginning of thought.” – Ashcroft v. Free Speech Coalition, 535 U.S. 234 (2002)