In a 6-2 decision, the Supreme Court Justices struck down a federal law that required recipients of government funds to declare that they were opposed to prostitution. The initial requirement of this declaration was intended for groups that received funding to fight AIDS and HIV, which could be spread more rampantly through prostitution.
The decision declared that the federal government did not have the authority to require these groups to agree to this viewpoint in order to receive funding because it violates the First Amendment of the Constitution. The First Amendment lists numerous freedoms including freedom of speech.
See more: Scotus