Privacy fears stoked by license plate readers

A license plate reader is mounted on the trunk of a police car in Washington, DC, on December 1, 2011
A license plate reader is mounted on the trunk of a police car in Washington, DC, on December 1, 2011.

US police departments are rapidly expanding the use of automatic license plate readers, sparking debate on whether the technology is a valuable crime-fighting tool or a massive invasion of privacy.

A recent report by the American Civil Liberties Union (ACLU) warned that these readers—used in patrol cars or fixed locations on streets and highways—collect data on tens of millions of Americans who have committed no wrongdoing, with a potential for privacy abuses.

The devices scan license plate numbers and match these against databases to help locate stolen cars, criminals or missing children. Backers say this can free police officers from a monotonous task and help solve crimes.

But with many Americans uneasy over government surveillance of the Internet, the expansion of this has sparked concerns about Big Brother.

"In our society, it's a core principle that the government doesn't watch people's innocent activities just in case they may connected with a crime," said Allie Bohm of the ACLU.

"In many cases, police are retaining this data indefinitely with few . The tracking of people is an . It can reveal people's political views, and a lot of other personal information."

The ACLU report, based on a survey of hundreds of US police departments, said almost three quarters of police agencies reported using license plate readers, and 85 percent planned to increase their use.

Only a tiny fraction of the license plate scans helped point to crimes or stolen vehicles, according to the ACLU survey.

It found that for every million plates read in the eastern state of Maryland, only 47, or 0.005 percent, were potentially associated with a stolen car or a person wanted for a serious crime.

There have already been abuses. In one reported case, a mayor asked police to track his challenger to expose a relationship with a mistress. In another, police scanned the plates of people at a political protest and then investigated them.

Few oppose using the technology to fight crime, but the ACLU and others say keeping data on millions of people for years, or indefinitely, can be troublesome.

The report said private companies may end up holding this data with no oversight or privacy protections, noting that one firm holds over 800 million license plate location records from 2,200 law enforcement agencies, including the US Department of Homeland Security.

"We don't object to the use of these systems to flag cars that are stolen or belong to fugitives, but these documents show a dire need for rules to make sure that this technology isn't used for unbridled ," ACLU staff attorney Catherine Crump, the report's lead author, said in a statement.

But David Roberts, who heads the technology center for the International Association of Chiefs of Police, said these devices have become "enormously valuable" in fighting and preventing crime.

"It automates what is a time-consuming process which officers do on a manual basis," Roberts told AFP.

"These can trigger automatic alerts. And this can have extraordinary value in locating vehicles wanted for a variety of reasons."

He noted that the technology can help in "noncriminal" cases such as locating elderly people who may be suffering from dementia.

Roberts said surveys by the association indicate around 75 percent of US police departments are using or plan to use license plate scanners.

And he said the technology is widely used in other countries, notably Australia, Britain and Canada.

Police departments are aware of privacy concerns, but Roberts said these can be minimized by having guidelines in place on use and access of the data, with "strict audits" to ensure that police don't user the data for "fishing expeditions."

The association does not recommend a specific length of time to retain data, but urges police department to have policies that allow access only for official law enforcement purposes.

"It's not accurate to say this is a tracking system." he said.

"What these produce is an image of a license plate in a public space. You still need to access motor vehicle records to find out who the registered owner is."

Authorities appear to be listening in some cases.

This year, Virginia's attorney general ruled that police may only use the technology for "active" criminal investigations. And Rockville, Maryland agreed to a system to share its data with a state agency that deletes the information after one year.

Even as the debate rages, it remains unclear how effective the technology has been in reducing or solving crime.

A 2010 study led by Cynthia Lum at George Mason University was unable to determine whether readers helped prevent auto theft or other crimes in auto crime hot spots.

Lum, a former police officer, said the study was limited in scope. She is seeking to conduct a comprehensive study on the impact on overall crime from the technology.

Lum, who heads the university's Center for Evidence-Based Crime Policy, said the technology is appealing because "it automates a process of investigation that police have been using for many years."

But she noted that the evidence on the effectiveness of scanners "is still underdeveloped."

"There is a chance you might acquire this technology and it might not give you the value in crime prevention that you anticipate," she said.

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© 2013 AFP

Citation: Privacy fears stoked by license plate readers (2013, September 8) retrieved 13 October 2019 from
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Sep 08, 2013
There's two ways you can use automatic lisence plate readers:

1) stream the data from the scanner to a central location for analysis, and then send alerts back if something interesting turns up, like a missed MOT or tax payment, or a stolen vehicle etc.

2) stream the data of interest to the patrol cars, and the scanner alerts the user when it detects a specific plate listed within. The system doesn't need to store any other data.

Option #1 has the obvious privacy problem of retaining information about who was where and when, even though they're not being investigated for anything. Option #2 works more efficiently: the police should only be looking for plates of known offenders, and disregard everyone else. If they're looking for John Smith, they should already know his car's plate numbers from the DMV.

There's no value in making an ID query for every plate you see and retaining the data back at the station, unless you're tracking innocent people on purpose.

Sep 08, 2013
Huge violation. No other way to look at it. The ends can never justify the means.

Sep 09, 2013
We had a huge discussion about this in germany a few years back - with the result that the scanning is now severely limited in scope. The danger is that one can very easily create profiles using this data which can lead to all kinds of (erroneous) conclusions.

I'll give you an example from a lecture we had (given by a policeman) on data security in 1990. He asked us if it was OK for a system to identify people by name on a debit card used in a cafeteria. The answer is: no way

If you analyse the sequence of people coming though a cafetreia by name you can find out stuff like:
- what time does someone go on break (unusually late/early; which can indicate missing social competence or lacking work ethic)?
- who's in front/behind them. Always the same people? Are these people trouble makers/union? If so he's a troublemaker/unionist by association (read: don't promote him)
- etc.

'Innocent' seeming information is not innocent in the hands of those who really want to interpret stuff.

Sep 09, 2013
Is driving a right or a privilege?

Rather than focusing on the collection of this data, focus on the access process. It should be tightly controlled, and all accesses logged (who, why, when). These logs should be audited by people we can trust. Individuals whose licenses have been scanned should be able to find out who is curious about them. Regardless of how long the license data is kept, these logs should be kept indefinitely.

The date itself is harmless. People in positions of authority who are willing to abuse that privilege are the problem.

Sep 10, 2013
Is driving a right or a privilege?

Driving is necessary for a great many. That's why it's subject to the right for privacy, because they can't reasonably avoid being monitored otherwise.

You can't force someone to effective house arrest if they don't want their every move tracked.

Sep 10, 2013
These logs should be audited by people we can trust

Problem is that those who we can't trust (and who would want to benfit from that data) have a big incentive of getting their people into those 'trusted' positions (secret service departments and the likes).

There should be (and there is in some countries) a right to "informational self-determination"

I.e. your data is yours. No one may collect data on you without your consent (exceptions: a court ruling or so called "overriding public interest").

Sep 10, 2013
The law was already successfully applied. E.g. in the 1980s the german government wanted to take a census. Some people sued against this based on their right to not divulge personal information - and consequently the idea had to be dropped.

in reality we are all scanned heavily with NSA

That in reality some institutions break laws isn't something one should accept.
While the mentioned law is particular to germany the US does have privacy laws. And government institutions SHOULD not be above the law.
That the people in the US have no problem with having their government exempt from laws (read: replete with privileges - i.e. "private laws") is their problem.

Not every country is a banana republic, however.

Sep 14, 2013
i bet this is similar to the state's argument for allowing gambling casinos to move into states because the states would get a share of the gambling profits to be used for schools and education. Trouble is as the states got gambling money they simultaneously cut their education budgets so the schools end up with budgets equal to pre gambling years. same for the police. with license plate technology they'll cut back on policemen . Budgets will shrink, less cops and fewer crimes solved than promised before license plate technology. no overall improvement but privacy will increasingly be compromised.

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