San Francisco officials may require nightclubs in this notoriously liberal city to scan identities of visitors and have cameras record comings and goings at establishments.
The Digital Age surveillance rules being considered by the San Francisco Entertainment Commission would apply to any venue where more than 100 people are expected to show up.
The Electronic Frontier Foundation (EFF) was among civil liberties advocates attending a commission hearing late Tuesday to object to the plan, which was proposed by police.
Commissioners put off discussion of the proposal to an unspecified future date and did not allow public comment at the meeting as originally scheduled, according to the EFF.
"These rules would pose a grave threat to the rights of freedom of association, due process, and privacy in San Francisco," Eva Galperin of the EFF said in a blog post.
"Scanning the ID's of all attendees at an anti-war rally, a gay night club, or a fundraiser for a civil liberties organization would have a deeply chilling effect on speech."
The rules would require people entering clubs or other venues to pass through metal detectors and have identification scanned into databases where the information would be stored for at least 15 days.
It would also be mandatory to have cameras record activity at venue entrances and exits, with the imagery kept for at least 15 days. Police would have the right to access stored data.
The proposal was crafted last year after someone was shot dead at a San Francisco club.