Surveillance

A California County Used Drones To Spy on Homes. A Settlement Will Now Require Warrants.

Sonoma County launched the program to find illegal cannabis grows, but it secretly morphed into a wider search for minor building code violations.

Mattha Busby | 9.3.2026 1:30 PM

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(Illustration: Midjourney)

A California county has agreed to effectively end a controversial warrantless drone surveillance operation that was launched to monitor unpermitted cannabis grows but secretly morphed into a wider search for innocuous building code violations. 

The program in Sonoma County, about an hour north of San Francisco, ultimately saddled homeowners with enormous fines for ordinary—and often disputed—code violations which residents said were punitive and aggressively levied. 

Over several years, dozens of residents were issued swiftly increasing fines, sometimes reaching six figures, and some had their properties foreclosed and were left homeless. The county issued at least $3 million in civil cannabis fines in cases involving warrantless surveillance.

In June 2025, the American Civil Liberties Union (ACLU) of Northern California and law firm O'Melveny & Myers accused Sonoma County of an illegal "runaway spying operation" and of violating the state constitution in a lawsuit on behalf of three affected residents. 

In a settlement announced Wednesday, Sonoma said it would use drones to fly over or monitor a home only after obtaining a warrant, except in certain limited situations such as emergencies. 

Sonoma's drone surveillance frequently found no unpermitted cannabis grows at all. Instead, drone imagery became a tool for ordinary code enforcement: unpermitted decks, trailers, fences, grading, outbuildings, and old cars. By 2023, 70 percent of drone flights ostensibly searching for cannabis found no cannabis violation. Records showed the county had amassed 5,600 photographs from 700........

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