There is a surprisingly robust legal history about sidewalk chalk as a medium of expression, most of it unfavorable to the chalkers.

In one of the earliest cases, McKinney v. Nielsen, a federal appeals court decided in 1995 that Berkeley, Calif., police lacked grounds to arrest an activist who disobeyed an order to stop writing an anti-police message on the sidewalk.

Although the “auteur” was charged under a city ordinance against defacing property, the chalking ended up being tangential to the case. The evidence established that the officers really arrested Christopher McKinney because he disobeyed an order to immediately drop his chalk — he kept writing long enough to stroke an underline — and because he back-talked the officers. Neither, in the view of the California-based Ninth Circuit U.S. Court of Appeals, gave police probable cause to make an arrest.

Except for last week’s [April 2012] Orlando ruling, courts have been generally unsympathetic to claims that chalking on public property is protected First Amendment expression.

* In Lederman v. Giuliani, a federal district court upheld the constitutionality of a New York City ordinance making it a crime to “write, paint or draw any inscription, figure or mark of any type on any public or private building or other structure,” including sidewalks. In a 2001 order, the court summarily threw out the constitutional claims of several street vendors who challenged the prohibition; the vendors prevailed, however, on their primary claim that the city could not require a permit to sell art or books on the street.

* In Mahoney v. Doe, a federal appeals court ruled last July that it was constitutional to prohibit demonstrators from chalking on the sidewalk across the street from the White House under a District of Columbia ordinance that bans writing, drawing or painting “any word, sign or figure” on public property without consent. The U.S. Court of Appeals for the District of Columbia Circuit found that the ordinance served a “significant” government interest (“the esthetic appearance of the street in front of the White House”), and left open reasonable alternative means of communication — the challenger had, in fact, obtained a demonstration permit that allowed the use of signs and banners.

* In Occupy Minneapolis v. County of Hennepin, a federal district court applied the same analysis as the Mahoney court, ruling in November that an unwritten county policy against chalking public sidewalks did not restrict the content of speech, and was justified by the “aesthetic interest” in maintaining a clean appearance at the county government plaza. The court noted that Occupy protesters had — and used — ample alternative forms of expression, including signs and leaflets, that required no marking of public property.