I worked at an international haulage company, and loved it there. Best job ever. But the day I caught a new manager going through someone else's emails was the day I knew the end was nigh. I was now a liability.

That manager made my life hell for a few weeks in the hopes I'd leave and take his little secret with me, but I was afraid I'd be framed for theft or something, so I looked for a new job. I found a new job very quickly, so I handed in my notice and worked my usual shifts until my last day. However I spent my notice period having fun with the computers. I am a trained typist - old school - and know a lot of typing tricks that can be used on computers, like….how to hide reams of information in full view on a page. Nothing illegal - I didn't change or alter the text, I just had a little fun with it. Then just for giggles I changed all the passwords.

Five weeks later I had a letter from them asking me for the new passwords. I ignored the letter.

Many months later I heard they'd had to call in a data retrieval specialist, who managed to break the passwords I'd set (they were easy). However, when they opened the manuals all the pages were blank. The manager had to throw away an entire operating system because I had hidden it in full view. They might be computer experts, but they weren't thinking like a typist.