I was thinking "gee, how about an ordinance prohibiting "sitting or lying on sidewalks:  Guess what "In the United States, a sit-lie ordinance (also sometimes referred to as sit-lie law) is a municipal ordinance which prohibits sitting or lying on the sidewalk or in other public spaces.

Proponents argue that such ordinances are useful or necessary in keeping sidewalks free from obstruction, particularly for use by mobility-impaired persons, and that they are a useful tool in fighting undesirable behavior, while opponents argue that they are instead veiled attacks on vagrants and homeless persons,[1] and, further, unnecessary and overbroad.

Sit-lie ordinances are most notably found in West Coast cities, since the 2000s, with Seattle, Washington, Portland, Oregon, and several San Francisco Bay Area cities – Santa Cruz, Palo Alto, and San Francisco itself – having passed such ordinances.[2]

In a 2009 survey of 235 US cities, 30% prohibited sitting or lying in some public places.[3][4]"