Earlier quoted context omitted.
Technically easy, operationally virtually impossible - everyone will slip up eventually. Also, the need for recognition often drives any human endeavour - and that leads hackers, criminals, etc to boast of their exploits to at least someone … who might be under observation, or under pressure to give up information to escape severe punishment for their own activities.
Prolly the need for recognition because if you hack from public wifi with tails tor mullvad, brand new laptop with specific hardware and so on I don't see how you can get caught up
Some parts of the internet never forget, and the anonymous graph is only anonymous if all of it is anonymous. 99.999% isn't good enough.