Cops throughout L.A. County, including LAPD officers and L.A. County Sheriff's Department deputies, are tracking your whereabouts through Automatic License Plate Readers (ALPR) mounted on patrol cars and light poles.

They don't know every place you are. But if you're spotted at a certain place at a certain time by an ALPR, not only can cops know it, but they can keep that data on file for years. The technology can theoretically provide for ah-ha moments: You were at the scene of the crime! 

But the ACLU is suing the LAPD and the Sheriff's Department:
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After the organization filed its opening brief in the case, senior staff attorney Peter Bibring helped to explain the organization's concerns with ALPR this week.

He cited LA Weekly's own reporting on the technology:

Already many agencies have created massive databases that record the travels of millions of drivers in a city, region or state. According to the LA Weekly, LASD and LAPD “are two of the biggest gatherers of automatic license plate recognition information,” logging 160 million data points, an average of 22 scans for every one of the 7 million vehicles registered in Los Angeles County. Agencies also share data, so that, for example, LASD can query license plate data from 26 other police agencies in Los Angeles County and is working to expand its reach to Riverside and San Bernardino counties.

See also: License Plate Recognition Logs Our Lives Long Before We Sin.

The ACLU is concerned that innocent citizens are being tracked with no probable cause that they've committed any crime. Bibring and Jennifer Lynch write:

Without proper safeguards, ALPR technology can harm privacy and civil liberties. A network of readers enables police to collect extensive location data on an individual, without his knowledge and without any level of suspicion. ALPRs can be used to scan and record vehicles at a lawful protest or house of worship; track all movement in and out of an area; specifically target certain neighborhoods or organizations; or place political activists on hot lists so that their movements trigger alerts.

The ACLU, along with the Electronic Frontier Foundation, are asking the court to grant them access to a week's worth of such license plate data collected by the LAPD and L.A. Sheriff's Department.

They want to know how police are using the info. Godspeed.

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