There are things we shouldn't disclose: that we cracked a website, bought cryptocurrencies and gold, robbed something, etc. To avoid being identified we must use technologies that allow anonymity (such as Tor and virtual private networks), pay in cash, and not show IDs, that's clear. However, we often forget something very basic: to be quiet.
Creating an anonymous digital identity, for example, is very simple: you register with a username on a website using a VPN or Tor and upload content. Losing that anonymity, on the other hand, is also very easy: just reveal some data related to your real identity. These digital identities can have data, but they must be false. The way we write can also reveal our real identity, so it's recommended to make an effort to change your writing style.
The people you interact with shouldn't know anything you want to keep hidden, even if they are people you trust. You never know if those people you trust today will still be trustworthy tomorrow. The con man who sold the Eiffel Tower twice, Victor Lustig, was arrested because his mistress became jealous of a relationship he was having with another woman and decided to rat him out.
Of course, many times we want to brag about our feats. We want to brag about our hacks, we want to show off.... Better not to do it. It's better to be humble and make up some excuse. “That's money my father gave me”; “I have cryptocurrencies, but not much”... In short, the best thing to do is to keep your mouth shut if you don't want to get caught and you don't want to be in the spotlight. Don't be the fool who brags about buying 100 grams of gold and the next day finds his house ransacked.