Because if you copy my MP3 for yourself then you are a single person who is not going to pay me (ie one potential lost sale). Not a huge deal. You probably woul

Because if you copy my MP3 for yourself then you are a single person who is not going to pay me (ie one potential lost sale). Not a huge deal. You probably wouldn't have paid for it if you couldn't pirate it anyway. If you then go out and sell that same MP3 then every sale you make is a sale that _I_ should have been paid for. The people you are selling to are willing to part with money and instead of it coming to me, the original author, it is going to a 3rd party.