Several Northern California law enforcement agencies have been connected to StingRay technology- a device used to assist law enforcement officials in tracking people and collecting data from cell phones within a set radius.

While none of the agencies that have been found to have a connection to this technology, records show that there are at least seven agencies in Northern California that do have the technology. Two other departments were approved for grants to purchase the technology this year.

Documentation shows that the US Marshals Service, Oakland Police Department, Sacramento Sheriff’s Department, San Diego Sheriff’s Department, Los Angeles Police Department and the Los Angeles Sheriff’s Department all use StingRay technology.

The primary reason that law enforcement agencies give to justify the purchase of StingRay technology is to fight terrorism. The Fremont Police, San Jose Police, Oakland Police and Alameda County District Attorney’s Office say that the technology can be used to track and disrupt networks of terrorists in the area.

Arrest records in Los Angeles and Oakland show that the StingRay is being used for routine police work, however.

This phenomenon, called “mission creep,” refers to the misuse of this type of surveillance technology. Agencies will offer one purpose for using the technology in order to justify collection of data. That data is then used for a completely different reason.

In Oakland, likely the first department to use StingRay, there were 21 arrests using the electronic surveillance in 2007. Nineteen arrests were made in both 2008 and 2009 for crimes including attempted murder, robbery, homicide and kidnapping.

The Oakland Police Department, however, will not admit to using StingRay technology.

Records show that the San Francisco Police Department was granted the funds for the same technology in 2009. The Sacramento County Sheriff’s Department is another agency listed as using StingRay, though it claims there is no record of having purchased the equipment.

According to USA Today, at least 25 different law enforcement agencies across the country use StingRay or similar cell phone spying technology.