My first 'hack' was helping write a program to format the floppy disks on Chromemco computers, as they did not provide one to the user. They made a lot of money for a while, selling you their pre-formatted 8" diskettes. I think they charged about 3 times the price of industry-standard blank media for theirs. Once the hack came out, they realized the game was up, and provided a formatter. Obviously, this was before DMCA, and sue-happy manufacturers.