In brief: Enabling location services for your smartphone apps can bring benefits, but a new report shows just how much it’ll cost you in terms of privacy. According to the New York Times, at least 75 companies dedicate to receive anonymous but very precise location data from about 200 million US mobile devices. It reveals people’s travels accurate to within a few years, and in some cases, the information is updated over 14,000 times per day.

While location data is anonymous and not tied to names or phone numbers, the NYT found that users’ daily patterns, such as where they sleep and places they visit, could be used to figure out their identity.

The Times tested 20 popular apps and found that 17 of them sent precise location data to about 70 businesses. One popular application, WeatherBug (on iOS), sent it to 40 companies. Out of these 17 apps, just three on iOS and one on Android notified users during the permissions process that their data could be used for advertising, while only one indicated it could be shared to “analyze industry trends.”

“These companies sell, use or analyze the data to cater to advertisers, retail outlets and even hedge funds seeking insights into consumer behavior,” writes the publication.

Some of the apps tested by the NYT include the Weather Channel, theScore, GasBuddy, DC Metro and Bus, Tube Map - London Underground, Perfect365, SnipSnap Coupon App, and Masha and the Bear: Free Animal Games for Kids.

The report arrives at a time when privacy has become one of the biggest issues for consumers. With Facebook and Google already under scrutiny for their use of customers’ data, reports such as this one could increase support for GDPR-style data protection regulations in the US.