The online world is exposed by default. It does not differentiate between what is public, private or secret for us. One's identity and data have 'market value', not our choice. This creates a conflicting situation between businesses and people.
As a user of multiple websites and apps in the internet world, it is easy for your identity, profile and data to be widely published, with your knowledge or not. If any of your personally identifiable data exists somewhere, be certain it is available for someone to dig out with little difficulty. Think of the never-ending promo messages and unsolicited calls we get daily. All that is needed is just one personal data to get the rest. It could be just an email id or a mobile number.
Identity theft, misuse and abuse have existed for enough time now. Pre 'app age', things were much simpler and controlled with limited or very specific 'hack opportunities' only. Thanks to our 'big move' to a predominantly online life now, invasion of privacy in numerous forms and shapes has accelerated full throttle. Each year millions of user records get compromised. Businesses spend a fortune in data security measures. Governments are framing new privacy laws every day.
Your financial, health, business and personal data, including the most confidential ids and passwords, will remain vulnerable unless you conciously take steps to protect them. One simple way is to ensure you do not give your data at random merely to experience a new app or product. Secondly, it is important that you become more aware of the importance of privacy in general and your own vulnerability in particular. In short, the only person that can help you is YOU. It is only you who should decide what is public, private and secret for you at any given time. Then make sure to choose the apps that honor that.