Scientists have discovered that some Android phone programs are secretly taking photos and videos on smartphones and sending them to third parties.
Android Phone Apps leak private data

According to the Gizmodo website, a group of scientists at Northeastern University in Boston experimented to determine if an application had recorded the user's call. It is reported that in one year, they have studied more than 17,000 of the most popular Android applications, including those belonging to the social networking site Facebook and sending Facebook data.
During the study, the researchers used different equipment. Scientists have not found instances where the application secretly turns on the microphone and transmits audio data. But they found that some programs took photos and videos that users made on their phones and passed the data to third parties. In some cases, the video contains personal information that has already been entered. Researchers point out that users don't always know that their behavior is being recorded because it is not stated in the "Privacy Policy" in a series of procedures.
https://www.alltekng.tk/2018/07/android-phone-apps-leak-data-to-third-parties.html

Reasons Google has been releasing periodic security patch update.