Police in Baltimore and surrounding communities have been using a service that monitors, maps and stores citizens' social media posts — a practice that has drawn the concern of civil libertarians.
Baltimore police say they have used the service, called Geofeedia, to monitor protests, parades and holiday celebrations. In Howard County, police used it to gather information and find people who needed help during the July flooding in Ellicott City, and after the Columbia Mall shooting in 2014.
Posts collected by law enforcement are archived in a secure data warehouse, according to documents obtained by The Baltimore Sun using the Maryland Public Information Act.
Civil libertarians warn that such monitoring can have a chilling effect on political speech. Police emphasize that they monitor only the social media posts that users share publicly.
"The only people that have anything to fear about anything being monitored are those that are criminals and attempting to commit criminal acts," Baltimore police spokesman T.J. Smith said. "We're not looking for what you did last night and your selfies and your Snapchats. We don't have time for that."
Smith said police search for "things that might be of concern," such as threats of violence. He declined to give details on how police conduct such searches.
Baltimore police have used an aerial surveillance plane to record footage of the streets below, and "stingray" technology that tracks cell phone signals. Aaron Mackey, a lawyer at the civil liberties watchdog Electronic Frontier Foundation, says such technologies raise questions.
"None of this is being used in isolation," Mackey said. "Are you seeing the community as an adversary in a war setting, or are you seeing them as the public you are serving?"
At least five area police departments use the service: Anne Arundel County, Baltimore, Baltimore County, Howard County, and Laurel.
Geofeedia, based in Chicago, did not respond to multiple requests for comment. The platform allows users to map out people's posts from Instagram, Twitter, Facebook, YouTube, Flickr and other social media outlets.
"Our patented technologies allow you to search areas as large as a city or as small as a single building across multiple social media services," the company said in a proposal to the city of Laurel.
Users can define specific areas to search and monitor, the company said. Content captured by users is archived in "our secure data warehouse."
A spokeswoman for Laurel declined to comment on how Geofeedia is used there. Anne Arundel County police, which also use Geofeedia, did not respond to questions about its use there.
Baltimore pays $18,000 a year for Geofeedia, according to its contract. Smith said police have used it to monitor protests, Fourth of July events, marathons and the St. Patrick's Day Parade.
Social media is "a regular investigative tool that any police officer should use because people talk, and people talk publicly," Smith said. "If you can glean information from something that's already public, you absolutely should take the opportunity to do so."
According to documents included in Geofeedia's contract with the city, Baltimore police can use Geofeedia to "continuously monitor and record social media." They can also set up alert notifications "triggered by specific keywords, phrases or users."
The city contract began in 2014 and was renewed in 2015, said Timothy Krus, the city's purchasing agent. The agreement did not need the approval of the Board of Estimates because it was under $25,000, he said.
Baltimore County last year entered into a five-year contract with Geofeedia that pays the company $20,000 annually.
"Geofeedia is used to observe real-time social media postings during critical incidents, such as a barricade or an active shooter, as well as for planning the department's response to a crime trend in a particular area," the county police department said in a statement to The Sun. "In addition, it can be used to help plan for community events."
The department emphasized that Geofeedia cannot collect information on private social media posts.
The county administration notified the County Council of the contract last year, spokeswoman Ellen Kobler said, but the purchase of software does not require the council's approval.
Geofeedia says on its website that it has uses beyond law enforcement. Retailers, for instance, can use it to analyze customers' social media use.
It's used by police departments throughout the country.
Police in Huntington Beach, Calif., have used the service for large sporting and community events, said Officer Jennifer Marlatt, a spokeswoman for the department. Officers look for key words such as "fight," "riot," "gun," "bomb," "shoot," and "drink," she said.
Detectives use it in "major investigations" to search for clues that could help them determine a motive, and to locate witnesses, Marlatt said.
Police have also used Geofeedia to monitor schools that are locked down by threats.
Police in Chicago use Geofeedia and programs like it to monitor public social media during "special events and notable incidents," spokesman Anthony Guglielmi said in an e-mail.
Lee Rowland, senior staff attorney with the ACLU's Speech, Privacy & Technology Project, said social media monitoring by law enforcement is a "burgeoning practice."
"There is absolutely no evidence that pervasive social media monitoring is effective at all," she said.
Rowland warned it can target religious and ethnic minorities disproportionately.
"It floods agencies with information on innocent individuals and conduct which just makes it more difficult to identify and respond to actual threats," she said.
She said contracts with private companies also raise concerns because details of the technology is often "kept as trade secrets."
There are also issues with due process, she said.
"Once the government has collected and retained a person's information, it can be almost impossible for a person to correct any errors in that information," she said. "The lack of any remedy or due process compounds the harms of the initial data collection itself."