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When law enforcement investigations get cold, there's a source authorities can turn to for location data that could produce new leads: Google.

Police have used information from the search giant's Sensorvault database to aid in criminal cases across the country, according to a report Saturday by The New York Times. The database has detailed location records from hundreds of millions of phones around the world, the report said. It's meant to collect information on the users of Google's products so the company can better target them with ads, and see how effective those ads are.

But police have been tapping into the database to help find missing pieces in investigations. Law enforcement can get "geofence" warrants seeking location data. Those kinds of requests have spiked in the last six months, and the company has received as many as 180 requests in one week, according to the report.

Google declined to answer specific questions about Sensorvault but said the company has narrowed how much identifiable information it gives police.

"We vigorously protect the privacy of our users while supporting the important work of law enforcement," Richard Salgado, Google's director of law enforcement and information security, said in a statement. "We have created a new process for these specific requests designed to honor our legal obligations while narrowing the scope of data disclosed and only producing information that identifies specific users where legally required."

For geofence warrants, police carve out a specific area and time period, and Google can gather information from Sensorvault about the devices that were present during that window, according to the report. The information is anonymous, but police can analyze it and narrow it down to a few devices they think might be relevant to the investigation. Then Google reveals those users' names and other data, according to the Times.

News of the law enforcement tactic comes as the tech industry faces intense scrutiny over its data collection practices. Facebook has been in the hot seat since its Cambridge Analytica scandal, in which user information from tens of millions of people was misused by a third party. Google has also been subjected to scrutiny after the AP reported last year that Google tracked people's location even after they'd turned off location-sharing on their phones.

It's not uncommon for law enforcement to seek help from tech companies during investigations. But the use of Sensorvault data has raised concerns about innocent people being implicated. For example, the Times interviewed a man who was arrested last year in a murder investigation after Google's data had reportedly landed him on the police's radar. But he was released from jail after a week, when investigators pinpointed and arrested another suspect.