How is Android App data accessed by other apps?

[AC Question]

I have a general question about Android app data, and how secure it is. I have noticed several apps on my phone display ads for ebay, showing items I recently viewed on my Ebay account, not necessarily via the app. So it seems clear these apps are looking at the content of my ebay account via the Ebay app on my phone. My next question, of course, is how to prevent such intrusions!
thanks

 

[Crashdamage]

Watch the permissions of apps you install. Don't install anything that wants to access anything it had no need to. Like a flashlight app that wants access to your contacts. Only install Apps from trustworthy sources, basically the Play store or Amazon.

The biggest security risk to Android is Android users. Be a smart user. Install Common Sense and use it at all times.


Android since v1.0. Linux user since 2001.