Recently I wanted to buy the particular product from an online website and was just searching that product during my leisure time. after some time suddenly I saw the ad of that product on Instagram and Facebook android applications. This blew away my mind because Facebook and Instagram Applications keeping track of activity I am performing on other application without my consent.
Anyone who is wise enough about privacy and security related stuff will never agree to allow other applications to track activities particular person is performing on other applications.
I have several doubts
How can Facebook and Instagram android application keep track of activities without any permission or privacy policy notification?
I know this mechanism is possible because of sharing of cookies between the apps but can only cookies are responsible for this?
Whether the same problem exists in the IOS as well? as IOS said to be more secure than android.
How secure application like banking applications restricts sharing of cookies with other applications?
Why there is no cookie specific permission feature available in android like we have access to give contact permission to certain apps camera permission to certain apps.