“Hundreds” of apps for Google’s Android platform failed to disclose third-party analytics and advertising services within them, which collected personal user information, according to a report.

“An analysis by University of Toronto researchers found hundreds of Android apps that disclosed the collection of personal information for the app developer’s own purposes — but, at the same time, didn’t disclose the presence of third-party advertising or analytics services that were collecting the personal information, too,” reported the CBC on Thursday. “If you give a weather app access to your location for a more accurate forecast, for example, a third-party advertising service embedded in the app could access it, too.”

Though it is the legal obligation for the app developer to disclose this, “hundreds” of apps did not, leaving users unaware about who was able to access their information.

Professor Lisa Austin, who was one of the co-authors of the study, called the results “eye-opening,” and declared, “This is one of the ways in which you’re getting tracked through your use of apps.”

“You can’t have informed consent if you don’t know that your information is being collected by these third parties,” she continued.

A report in August disclosed that Google tracks a user’s location via its apps even if the user had turned off the location feature. Later in August, a study found that Google’s Android smartphone operating system collects 10 times more data on its users than comparable iPhones.

In 2017, Google removed 500 “spyware” apps from the Google Play app store.