A license-plate reader mounted on a San Leandro Police Department car can log thousands of plates in an eight-hour patrol shift. “It works 100 times better than driving around looking for license plates with our eyes,” says police Lt. Randall Brandt.Michael Katz-Lacabe

You’ve heard how the NSA is snooping on your data, but what about local law enforcement?

Ali Winston and G.W. Schulz have been looking into local governments’ growing surveillance infrastructure – most of which is legal.

Winston and Schulz will be on Reddit on Tuesday at 11 a.m. PT to take your questions and comments about facial recognition technologies, biometrics, license-plate scanners, fusion centers and more. What are some examples of how cities have used these technologies? Do they keep us safer? Who is paying for it? How do people feel about these new policies? How is all this intelligence data being stored?

For a primer on how local agencies are using surveillance technology, here are a few cases we’re following. If you have more examples, let us know in the comments below.

  • Facial recognition technology: In San Diego, law enforcement agencies are deploying what could be the largest expansion of facial recognition technology for civilian use. The Tactical Identification System allows law enforcement officials to use a mobile device to snap a photo of an individual and run the image against a database matching criminal history, mug shots and other personal information of about 348,000 arrestees in San Diego County. “If you’re not in a criminal database, you have nothing to hide,” said Officer Rob Halverson of the Chula Vista Police Department. While officials value the efficiency of being able to easily identify someone, critics argue that how that information is stored – especially for those who have done nothing wrong – raises serious privacy concerns.
     
    More: The rollout of facial recognition technology in San Diego and its military tieshow facial recognition technology works 
     
  • Oakland’s Domain Awareness Center: In the port city of Oakland, Calif., a federally funded Domain Awareness Center is being expanded to allow local agencies to track Twitter feeds and use license-plate scanners, gunshot detectors, crime mapping software and stationary cameras. The Domain Awareness Center began as part of a nationwide initiative to secure ports by networking sensors and cameras in and around the facilities. The project will cost an estimated $10.9 million to complete.
     
    During a city council meeting in July, Oakland residents protested the city’s decision to accept additional funding to streamline intelligence gathering by incorporating data across different agencies, including local and state departments of transportation, the city’s school district and sports/entertainment venues like the O.co Coliseum and Oracle Arena.
     
    More: The progress of Oakland’s surveillance center and the debate around data collection
     
  • License-plate scanners: One technology law enforcement agencies in California are using is scanners that sit atop police cars. The scanners document license plates and geographic locations of cars passing by – even when drivers have done nothing wrong. Winston reported that “the intelligence center database will store license-plate records for up to two years, regardless of data retention limits set by local police departments.” Critics are concerned about how this data is being stored and the privacy implications.
     
    Last year, following a California Watch investigation that revealed a private company was stockpiling half a billion records on drivers using license-plate scanners, state Sen. Joe Simitian, D-Palo Alto, attempted to increase privacy protections. But under pressure from lawmakers and lobbyists, he backed away from his bill to regulate how such data is stored.
     
    More: Private company hoarding license-plate data on US driversLicense-plate readers let police collect millions of records on driversPolice, lobbyists defeat bill to regulate license-plate scannersDEA launches license plate scanners along border
     
  • Your digital trail: Schulz has reported that, “Many Americans would be surprised by how easily local law enforcement, IRS investigators, the FBI and private attorneys can reach into the vast pool of personal information about their lives with little more than a subpoena, which no judge needs to review.” Your medical records, online dating profiles, public transportation records, even unopened emails – all of these things can be accessed with a subpoena or court order by private investigators, private attorneys and local law enforcement officials.
     
    More: Easily obtained subpoenas turn your personal information against you; Watch how private companies track your digital trail, even when you’re not signed in

Check in to Reddit at 11 a.m. PT Tuesday for the live chat with Schulz and Winston.

Kelly Chen is a news engagement specialist at The Center for Investigative Reporting. She manages the day-to-day social media strategies and online engagement for CIR. In addition, she works to break down complex issues and ideas and create content for CIR's online communities. Kelly also works to increase engagement on cironline.org and on other online platforms. Previously, she produced discussion segments for PBS NewsHour and oversaw social media and engagement efforts for the American Graduate project, a public media initiative on the high school dropout crisis. She's also worked at Southern California Public Radio and National Geographic TV. A native of Los Angeles, she studied international relations and English at UC Davis.