Potential For Mistakes

Potential For Mistakes

As surveillance tools become more powerful and more pervasive, national security and law enforcement agencies increasingly depend on them to identify potential suspects. But mistakes are inevitable.

We're all capable of mistakes, but I do not care to enlighten you on the mistakes we may or may not have made.

Dan Quayle


As surveillance tools become more powerful and more pervasive, national security and law enforcement agencies increasingly depend on them to identify potential suspects. But mistakes are inevitable. Information can be recorded incorrectly, data can be retained when it should be deleted, automated analysis can produce errors and bits of data taken out of context can be misinterpreted. There errors may not be detected and can lead agencies to make serious mistakes.

Mass surveillance increases the problems that mistakes create. According to a secret internal audit leaked to reporters, in one year the NSA logged 2,776 incidents of illegal collection, storage, or access of private communications data. (This number only includes incidents found at the agency’s headquarters. If the audit had included the NSA’s other units, the number would likely have been much higher.) In one jarring instance, the NSA intercepted a “large number” of phone calls to and from Washington, D.C., due to a simple typo:  The agency’s computer system confused the D.C. area code (202) with Egypt’s country code (20).

Similarly, the U.S. government maintains several massive “watch lists” of possible terrorist suspects. Agencies frequently add names to these lists based on unreliable, outdated, and poorly reviewed information. The result is a blacklist of over a million names that is not properly vetted or updated. The list has included members of Congress and their family members, U.S. military veterans, movie stars – even Nelson Mandela. The people on these lists face travel restrictions, screening or interrogation at airports and border crossings, traffic stops, and perhaps even clandestine surveillance in the communities where they live.

If you are improperly caught in the surveillance dragnet or if the government has inaccurate information about you, you have few options. Government agencies typically conceal the capabilities of their surveillance systems and the contents of their databases. If incorrect information lands you on a list of criminal suspects, you may never have the opportunity to review that information and correct it. In 2012, for example, 53 nonviolent anti-war and anti-death penalty activists received letters from the Maryland State Police informing them that the MSP’s anti-terror surveillance unit had labeled them terror suspects and loaded records of their information into federal databases.

Examples of Use

  • Map of California featuring San Francisco
    San Francisco, CA
    Errors Lead To An Expensive Settlement

    On a cool evening in March 2009, Denise Green was driving her burgundy Lexus through San Francisco. A little after 11 pm, she passed a police cruiser equipped with an automatic license plate reader. The ALPR scanned her plate and returned a “hit,” flagging it as belonging to a stolen vehicle. The tracking device, however, had misread the plate. The actual stolen vehicle was a gray pickup truck, not a burgundy sedan. Regrettably, the San Francisco Police Department had no formal policy mandating that officers verify both the plate number and the model and color of the car, either of which would have clearly revealed the mistake. The officer radioed nearby units to assist him in stopping the vehicle. A police sergeant in the area opted for a “high-risk felony” stop. He pulled her over, and he and four other officers approached her car with guns drawn, handcuffed her, and conducted a field search of the car that exposed their mistake. Green sued the city. The incident cost the community hundreds of thousands of dollars, which could have been saved had the SFPD required its officers to use independent judgment in ALPR stops, rather than relying solely on fallible technology.


When government agencies consider acquiring and using surveillance systems, communities and their elected officials must both weigh the benefits against the costs to civil liberties and carefully craft policies and procedures that help to limit the negative effects that surveillance will have on fundamental rights.  For a useful list of considerations, please visit the recommendations page.

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