To those calling him out for hacking his friend without permission, keep in mind he was a teenager (15) at the time. His friend was of similar age. Teenagers do stupid things, I was of similar age at one point and also did very stupid things. It's part of growing up. Saying that, the author needs to give better context.
Yes, but he didn't write it as a cautionary tale or even attempt to portray it as a stupid thing done out of youth. The delivery very strongly portrays it as a good thing that was a good idea, and a rational step towards advancing yourself in the world.
A mechanic reading a tale of someone pouring metal filings in with the engine oil, I doubt they're going to think it's a good idea to go out and ruin their engine.
Is an author always required to include a disclaimer? Stupid is as stupid does.