Reminds me of a time...
Must have been around 15 years ago now. While enjoying a bottle of wine I thought I would peruse their website, and they were running a competition to win half a dozen bottles. On attempting to enter the competition, I found that the script wasn't working, so I went through the source code and figured out how to submit my entry.
A few weeks later I found out that I had won the competition, and duly received my free wine. And it was only then at that point that I realised I could have entered multiple times from multiple email addresses (and with multiple physical address locations as well, e.g. parents, work, etc) and therefore won multiple prizes. I may have been the only person to enter the competition unless someone else had also figured out the submission issue...