I probably have nothing to worry about, but..
Ok, so I have some software my friend lent me, and I installed it with a serial number I had found. The software then registered itself with the company with that serial number (which I'd imagine has been used by many people). Do I have to worry about the company coming after me for using software that I didn't pay for? I probably sound like an idiot right now, but I have nothing to worry about right? I'm sure that there are some duplicate s/n's out there, so I don't know