Its interesting but never really one for selfies...though possibly every you type into your device, it secretly records your every move and facial gesture and fingerprints.
The next thread might be are you brave enough to give out your credit card number?
There's a basic difference between being "Brave" and being foolhardy.
A couple of years ago, I walked into two different banks in Fort worth, and withdrew funds, and the next day went into two different banks in Memphis, and withdrew about $6,000 from my account. when I did the withdrawals, they took my picture, and I was dressed the same in all instances.
Except, of course, it wasn't me. But whoever it was HAD MY BANK OF AMERICA SAVINGS ACCOUNT NUMBERS (which I have never posted publically for any reason). My funds were restored by the bank, but I learned some things about "account security" that surprised me -
Chances are that everything you're worried about them "Finding out", they already know.
One of IBM's early jobs in the '40s was leasing equipment for cataloging Jews, and managing the "camps" for the German Government.