(AP) — Extraordinary use of electricity has long been a telltale sign of illegal grow houses producing thousands of marijuana plants hidden in seemingly ordinary homes.

But a lawsuit filed by a data privacy watchdog says a Northern California utility went too far by racially profiling Asian communities as it routinely fed customers’ power use information to police without requiring a warrant or any suspicion of wrongdoing, in violation of state laws.

The data disclosure deliberately targeted Asian Americans, with resulting disproportionate penalties against those of Asian descent, the suit says.

The suit illustrates a flashpoint in law enforcement’s efforts to combat illicit drugs.

In 2018, federal and state law enforcement agents seized about 100 Northern California houses that they alleged were bought with money wired to the United States by a Chinese-based crime organization, one of many such actions against alleged perpetrators of Asian descent.

Earlier this year Asian Americans filed at least two lawsuits against Siskiyou County’s sheriff alleging racial bias particularly against the Hmong community in his department’s effort to combat widespread illegal marijuana cultivation.

The Sacramento Municipal Utility District scoured entire ZIP codes worth of power usage information for the Sacramento Police Department but left out homes in a predominantly white neighborhood, says the lawsuit. And a police analyst removed non-Asian names from a list provided by the utility, forwarding only Asian-sounding names for more investigation, the suit claims.

The utility would turn over a list of customers who used more than a certain threshold amount of energy in a month, the lawsuit alleges. For instance, while a typical household might use less than 1,500 kilowatt hours of electricity in a month, the suit says the utility would disclose homes using more than 3,000 kWhs.

The bulk disclosure “turns its entire customer base into potential leads for police to chase,” the lawsuit says. It says the utility “liberally discloses” customers’ Social Security, driver’s license and telephone numbers.

SMUD and Sacramento police said they couldn’t comment on pending litigation, but SMUD spokeswoman Lindsay VanLaningham denied any wrongdoing.

“We agree that our customer usage data should be (and is) treated with care,” she said Thursday, but she said state law allows and sometimes requires sharing the information with law enforcement agencies.

“We share the information on specific properties to stop what we’ve identified and believe to be power theft and when we are required to do so per local law enforcements’ request to assist them with their investigations,” she said in an email.

“We look forward to being available for questions once legal proceedings have concluded,” Sacramento police Sgt. Zach Eaton said.

The suit was filed Wednesday by the watchdog Electronic Frontier Foundation on behalf of the nonprofit Asian American Liberation Network and SMUD customer Khurshid Khoja, who is described as being an Asian American Sacramento resident, cannabis industry attorney and cannabis rights advocate.

Megan Sapigao, co-executive director of the network, said the “mass surveillance program is unlawful, advances harmful stereotypes, and overwhelmingly impacts Asian communities.

“It’s unacceptable that two public agencies would carelessly flout state law and utility customers’ privacy rights, and even more unacceptable that they targeted a specific community in doing so,” she said in a statement.

EFF Senior Staff Attorney Aaron Mackey said the foundation isn’t aware of any other California public utilities that are sharing data in the same way as SMUD.

Private utilities like Pacific Gas & Electric, Southern California Edison and San Diego Gas & Electric are barred from disclosing customer utility data to law enforcement without a court order under state law and California Public Utility Commission rules, he said.

Public utilities like SMUD aren’t regulated by the commission, but state law bars them “from disclosing entire neighborhoods’ worth of data to law enforcement absent a court order or ongoing investigation,” Mackey said.

SMUD is the nation’s sixth-largest community-owned electric service provider, serving more than 600,000 customers, the suit says.

Southern California Edison’s policy generally requires a warrant or subpoena to share information with law enforcement. The other two major private utilities did not immediately respond to queries from The Associated Press about whether they have similar information-sharing programs, nor did the California Public Utilities Commission comment.

The lawsuit comes as officials are struggling to curtail illegal cannabis grows that are stunting the growth of the legal, licensed recreational marijuana production that California voters approved in 2016.

Disguising illegal cannabis farms in ordinary appearing homes became prevalent nearly two decades ago as authorities disrupted outdoor plots they could spot from helicopters and other surveillance flights.

Law enforcement authorities often discovered the illegal grow houses because of their extraordinary use of electricity to run high-intensity lights, ventilation fans and other devices to grow thousands of marijuana plants, often enabling several harvests each year.

Sometimes the tipoff came when the houses caught fire due to illegal electrical hookups.

Sacramento officials estimated in 2017 that there might be as many as 1,000 illegal grow houses in California’s capital city.

The foundation said the crackdown “has been highly lucrative” for Sacramento, since a city ordinance in 2017 allowed police to levy large penalties on the owners of properties where marijuana was found.

The city issued nearly $100 million in fines in just two years, the foundation said, about 86% of them on people of Asian descent.

The privacy violation is more acute with the proliferation of “smart” meters that send power usage information to the utility several times a day. That information, collected in increments of 15 minutes or less, can provide “a detailed picture of what occurs within a home,” the foundation said. “It can provide inferences about private daily routines such as what devices are being used, when they are in use, and how this changes over time.”