By staking claim to public space, Critical Mass rides are a powerful means of supporting First Amendment rights to free speech and free assembly, according to this piece from Yes! Magazine.
Critical Mass bicyclists are supporting [the First Amendment] by saying that it is their only required permit. The rides are peaceable assembly. Their free expression comes in an intriguing form-the act of traveling by bicycle up streets and down avenues where defenders of the internal combustion engine have built a thick book of pre-emptive, car-friendly laws.
Critical Mass is leaderless and has no set route for its parades. To the cops it is like a mirage. Something in the sinu-ous mystery of the rides makes them gravitate to their power. The uninstructed bicyclists slowly circle out from Union Square and might suddenly take a hard left up 16th Street in an act like the flock-mind of birds. They just go.
Critical Mass represents freedom in public space, where ads, cell phones, surveillance, and traffic jams have melded together to make sections of Manhattan the outdoor equivalent of a privatized (First Amendment-free) super mall. These bikers don't wear logos; they are not en route to a purchase. The bicyclists are opening up public space as citizens see them wheeling by, and their trips through the city are ushered forward by a rolling citizens' cheer. Critical Mass bikers make it realistic that there is more in life than consumption, and people who see them feel relieved.