The US Immigration and Customs Enforcement (ICE) agency has signed a contract with Vigilant Solutions, which owns a database of two billion images of license plate tagged with dates, times, and GPS coordinates.

How it could work: According to the Verge, ICE agents could use the database to perform searches that would show every place a license plate was spotted in the past five years. That would allow agents to build a clear profile of where and with whom a person spends time. The system can also send real-time e-mail alerts for new photos of a particular plate.

Taking issue: The ACLU warns that the technology, ostensibly meant for tracking down undocumented immigrants, could be turned into a tool that tracks all Americans.