That's terrible news. How should we avoid it?
Don't tell anyone about what you are holding , just don't talk crypto with anybody .
Even if you trust them , they can tell someone and that is how it goes.
Just pick one person you really trust that in case something happens to your coins aren't lost.
If you hold a big amount maybe make a separate wallet , in case stuff like this happens you just give them a small amount of your stash.
But stuff like this will happen more and more as crypto gets more populair , so be safe.
but if you are using crypto to pay for stuff in public or for buying crypto in person it is hard to conseal the fact you have it.
Best thing as above is to keep a crypto low profile and make a dummy wallet with a nominal amount of currency on it.