Welcome to Californistan - This kind of garbage is why the people north of Chico want to form the state of Jefferson... along with what they feel is *zero* representation in Congress.
It's worth noting that this Ordinance has been on the books for at least a few years and includes Golf, Hang Gliding, Fireworks and a couple others..
3.68.150 Dangerous Activities
Except in areas specifically designated and set aside from time to time by the
Parks and Recreation Commission, or the San Francisco Water Department
for such activities, no person shall engage in any of the following activities
within any County Park or Recreation area, or on the San Francisco Fish and
Game Refuge, and in no case shall any person engage in any activity or
operate any device recklessly or negligently so as to endanger the life, limb
or property of any person:
1. Use or possess fireworks of any kind.
2. Drive, chip, or in any other manner play or practice golf, or hit golf
balls.
3. Operate self-propelled model airplanes, boats, automobiles, or
other model craft of any kind or description.
4. Throw, release, or discharge missiles, rockets, or similar projectiles.
5. Hang-glide or parachute.
6.Operate any gas or hot air balloon (other than a toy balloon).