Law enforcement agencies like the FBI and the DEA already use license-plate tracking. The DHS wants access for its Immigrations and Customs Enforcement agency, so it's asking for bids from database companies to see how much they would charge field officers. While commercial databases are not bound by limitations on the number of years they can hold on to the data, the DHS will be imposing a five-year limit. And access will be crime-based – agents will need to punch in the details of the associated crime to get the information. Where the red flag for privacy advocates comes in, is an "alert list" for people of interest. It gives the department "warrantless" access to drivers, and many argue that's too low of a legal threshold for data that can easily reveal so much about anyone targeted.