California
San Mateo County
On record
Checked 21 Aug 2026- Technologies
- 1
- Systems
- 1
- Devices mapped
- 826
San Mateo County, California. Device data © OpenStreetMap contributors (ODbL), with community reporting via DeFlock. Open the full map →
San Mateo County is the most thoroughly counted plate reader county on this site, and it was counted by the county itself. In August 2026 the civil grand jury published a review of automated license plate reader use by eighteen law enforcement operators here, with a camera census, the policies, the contracts and the network sharing tables.
More than 582 plate reader cameras were deployed across the county as of March 30, 2026, nearly all of them from one vendor. Every police department in the county operates them except Broadmoor. The Sheriff’s Office is the largest operator, and also runs the systems in Half Moon Bay and Woodside.
We have published the Sheriff’s system, built on the office’s own policy read in full. The other seventeen operators are named in the grand jury’s report but no primary document from them is in our corpus, so their compliance findings on this site remain the grand jury’s rather than ours.
Local news coverage of this county has not been swept, and no meeting archive has been searched for the decisions that approved these cameras.
What's in use here
The Sheriff's own policy purges Flock camera data after thirty days, one of the shortest retention periods this site has recorded, and bars sharing with federal and out-of-state agencies. The same policy states that no suspicion is required to run the system, and the county's civil grand jury recorded the office as having no stated retention period at all.
Who runs it
The agency is the accountability unit: who voted, whose policy applies, and who answers a records request.
| Agency | Jurisdiction | SB 34 policy | Systems |
|---|---|---|---|
| San Mateo County Sheriff's Office | San Mateo County | Posted | 1 |
| 1 agency on record. A jointly run system counts against each of its operators, so this column is not a county total. "Posted" means the policy is published where the law requires it. "On file" means we hold the document. "Not posted" and "not found" mean we could not find it on the agency's own website on the date shown; they say nothing about how the system is used. An agency with a dash has not been checked, which is not a finding. | |||
Trackers
Meetings, contracts, records
Nothing listed yet. The trackers launch here, and facts appear only with their sources.
How the inventory works →What you can do
Civic action
Show up
Public comment is open to any resident, and you do not have to be an expert to use it. We have not yet confirmed where the bodies that decide for San Mateo County meet. How the inventory works explains what we check and how to check it yourself.
How the inventory works →Personal protection
Protect yourself
Practical steps to shrink your personal data trail. Our guides publish at launch; until then, EFF's Surveillance Self-Defense is the best starting point.
Surveillance Self-Defense ↗Get the digest
A regular digest of what changed in the world of surveillance: the counties we published, the devices that appeared on the map, and the public meetings where these decisions get made. We send it when there is enough to report.
One click to unsubscribe. What we do with your address is on the newsletter page.