Haight-Ashbury is famous for its street people, but the mayor apparently has had enough after seeing a man on the sidewalk smoking crack.
Police say they're hearing more complaints like that from residents fed up with aggressive, intimidating uncivil behavior
"She was with her 14-month-old son, she was walking down the street and she asked a group to move and they spat on the baby," Capt. Teresa Barrett from SFPD said.
Police tell San Francisco supervisors they're backing a so-called sit-lie law that would make it illegal to block the sidewalks.
Critics say there are already laws on the books that simply need to be enforced, but according to police someone has to make a formal complaint before an arrest can be made.
The new proposal would allow officers to issue warnings and citations without that.
"The goal here is not to arrest people. It's to change behavior," Assistant SFPD Chief Kevin Cashman said.
But those who hang out on the streets see it as an attack on the poor and homeless.
"I feel basically, personally accused of doing something that is really not that harmful to anyone around me," Rider Murray said.
Critics of the proposal spoke out on the steps of City Hall including the president of the Haight-Ashbury Neighborhood Council.
"By making anyone who sits in the street a lawbreaker, it creates a new class of criminals where none existed before," Joey Cain said.
But another neighborhood group, the Haight-Ashbury Improvement Association supports the crackdown and brought in the mayor of Santa Cruz to speak at a public hearing on Monday.
Mike Rotkin initially had reservations when the measure took effect in his city, but now says it is working.
"After we passed the ordinance it took only a couple of weeks before we began to see changed behavior," he said.
"I don't see why we can't occupy a square of sidewalk and try to get by and exist, co-exist," a homeless person said.
Newsom is expected to present two proposals on Tuesday: One would be a city-wide ordinance and the other would target certain commercial corridors like the Haight and the Tenderloin. San Francisco had a sit-lie ordinance back in 1968, but it was successfully challenged in court.