I've never done anything explicitly illegal in the context of programming, but some opportunities which fall in the gray area of legality are just too tempting

I've never done anything explicitly illegal in the context of programming, but some opportunities which fall in the gray area of legality are just too tempting to pass upon. I did consulting in reverse-engineering and provided documentation and tool too exploit certain vulnerabilities. Provided that I never used those tool myself for profit, the liability falls onto my clients, considering that I also signed a contract explicitly stating that. The reason why I loved doing this work so much is because it was highly challenging, considerably more complicated than any software engineering job I ever had before. And more importantly I was extremely good at it, and more often than not I discovered something which no one ever did before. It felt like a mix of software development and scientific research. Unfortunately when it comes to reverse-engineering, there are not many strictly "white hat" applications for it, besides pentesting and security audit. And naturally I missed building things and creating something which would actually make people's lives better.