I'm pretty sure you can't, despite what IP holders would like you to believe. Like the last 50 years of piracy have taught us, it's effectively impossible (and

I'm pretty sure you can't, despite what IP holders would like you to believe. Like the last 50 years of piracy have taught us, it's effectively impossible (and probably immoral) to try to charge for copying something that's "free" to copy. It might make more sense to update copyright laws to match reality. For a music artist, for example, pennies from Spotify mean nothing -- the majority of their revenue comes from concerts/events, merchandise, and commercial licensing of their work.