The city of San Francisco on Monday removed about two dozen small boulders from a residential side street after a group of neighbors had them installed last week in an effort to deter homeless people from camping out on along the sidewalk amid the city’s ongoing crisis.
https://www.foxnews.com/us/san-francisco-removes-boulders-homeless-clinton-park-neighbors

I understand there was a problem with placement. The city removed the offending boulders. San Francisco authorities are now in consultation with Salem, Massachusetts historians in order to determine the proper placement of boulders.