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The American Civil Liberties Union is calling for new rules to govern the use of license plate recognition (LPR) technology that supporters of the program say helped catch the Boston bombers and the man responsible for the attempted 2010 car bombing in Times Square.

The technology, which has become popular in the past decade, lets police officers potentially determine a person’s location at the time of a crime by running plate numbers through secure databases maintained by individual states. It is presently used in every state, the ACLU says. A former police commander familiar with both the Boston bombing and the attempted bombing in New York said LPR was a factor in solving both cases.

"I know LPR was used extensively in both of those investigations," the retired cold case commander for a major metropolitan police department told FoxNews.com. "I can't convince you enough how important [it] is in helping law enforcement solve cases."

The ACLU’s problem with LPR technology isn’t that it simply records plate numbers that can later be reviewed by police. LPRs also store photos of the plates, which the ACLU has labeled a potential breach of privacy.

"The fact that this technology is trying to be limited in its capability, I don't think anyone is thinking about the victims here."

"License plate readers can be used for tracking people's movements for months or years on end, chilling the exercise of our cherished rights to free speech and association," the watchdog group wrote in a recent report. "Location data can reveal extremely sensitive information about who we are and what we do."

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Others disagree.

"License plates don’t have anything to do with people. It’s a piece of metal with a number on it," said Steve DelBianco, executive director of NetChoice, a trade association of eCommerce businesses and online consumers.

LPR technology uses cameras on police cars, traffic lights and other transportation spots to capture images of passing plates, as well as their location, with a date and time stamp. The information is then collected in a state database that local law enforcement can access and refer to during investigations.

Police used the technology to confirm the identity of a suspect in the attempted car bombing of Times Square in 2010.

"The car [found smoking at the scene] had its VIN [Vehicle Identification Number] numbers eradicated, but it did still have its license plates," the source explained. Police tracked the plate to a man in Connecticut who had reported it stolen several months earlier. "It came up three times in Bridgeport, Conn., where they already had a potential suspect."

In the case of the Boston bombings, once police identified Tamerlan Tsarnaev, they ran his license plate number using LPR technology to find locations Tsarnaev visited in the times leading up to the bombing, according to the source. By discovering the places he frequented, law enforcement could find potential accomplices.

"An investigator with intimate knowledge could make reasonable deductions," the source told FoxNews.com.

The ACLU declined to comment to FoxNews.com, after repeated attempts to reach the group over multiple days. But one representative recently argued that LPR technology violated many rights, including a person's right to privacy.

“We understand that these are tools that make it easier for law enforcement to do their work,” Shelli Weisberg, legislative director for the American Civil Liberties Union of Michigan, told the Detroit Free Press. “But these technologies are advancing very, very quickly and our laws are not keeping up with the collateral damage of information they gather on everyday citizens.”

Some argue that the Driver’s Privacy Protection Act already exists to protect the privacy of citizens. That act bans "any use of personal information obtained from motor vehicle offices without consent unless it is for specific purposes authorized by the law, such as for law enforcement."

DelBianco points out that license plate numbers, like VINs, are out in public and therefore can be photographed by anyone.

The ACLU agrees. With respect to the right to public photography, the group wrote: "When in public spaces, where you are lawfully present, you have the right to photograph anything that is in plain view. That includes pictures of federal buildings, transportation facilities and police.”

Sgt. Kyle Hoertsch with the Sacramento County Sheriff’s Department uses LPR tech provided by Vigilant Solutions. "Everybody gets tied up on license plate readers," Hoertsch told FoxNews.com. "I appreciate what the ACLU is trying to do, but I think they might be misguided on the information they're putting out."

Hoertsch says his department has been using Vigilant Solution's tech systems since January. Based on an 8-hour sweep he conducted using 27 LPR-equipped police cars on Oct. 30, he recovered 30 stolen vehicles and made 25 arrests on outstanding warrants. "The data is giving us more than we can handle," Hoertsch said.

Brian Shockley, vice president of Vigilant Solutions, insisted that LPR respects privacy. "The data collected is completely anonymous and there is no identifiable information," he told FoxNews.com. "Facebook and Twitter present a bigger privacy issue."

"I don't think anyone is thinking about the victims here," the source told FoxNews.com. "I've had to make death notifications to families to tell them their loved ones are victims of murders. To go back and tell them we're done and can't solve it -- LPR can change that."