The answer is "the right of a group to meet".
The right to peaceably assemble is one of the five freedoms ensured in the First Amendment, yet that opportunity does not really reach out to private property.
The right to peaceably assemble implies that somebody can assemble with others without dread from the administration that they are a crowd. Individuals can get together with whomever they need as long as they are quiet and not causing inconvenience. This applies to all gatherings, regardless of whether individuals don't care for those gatherings.
