It is extremely difficult to maintain any control of the data you hand over to companies. Some apps will state that they will delete your data off their servers once you delete your account, but it can often be very hard to delete parts of your information while continuing to use the services. The best way to control who shares your data is to limit the amount you offer in the first place. When installing an app it can be very easy to simply hand over your data or access to your photos and contacts without a second thought. However, once this control is lost, your information can very quickly get into the wrong hands and be abused by cybercriminals. Targeted advertising is one thing, but abuse of data for unlawful usage is another kettle of fish all together.  Read Less