I have a crazy neighbor that is totally 100% without a doubt convinced that others in our area are getting paid per month to keep the trees on their land. He tells me things about how the government comes once a month or so to verify that the trees are still there before issuing the big check for this month. It is really interesting to see what other people are out there thinking.
Your customer probably got some kind of twisted fact like that from the companies that sell programs to copy DVD's. They typically issue claims about "fair use" and such.
My girlfriend bought a copy of a program called "MP3 Rocket" years ago. The program makers said with it you could legally download thousands of songs, etc. If you've never seen the program, it's just a clone of an illegal program that you can download music with. She could have found the exact same thing that doesn't say MP3 Rocket for free and it's just another peer to peer music program. It does make her feel more justified that some website said it was legal software tho and she did pay something ($20) to use it. Shes told me that if she ever gets in trouble for file sharing, she'll use the defense that she thought it was legal because of what the program says. Doubt this would work but oh well
