The relationship between private copying levies and digital rights management tools is a major challenge in copyright law.
Different types of copyright-holders generally prefer different approaches. Individual authors and performers and their representative societies have favourable attitudes towards levies, while major producers and distributors tend to prefer the control digital locks provide.
I spoke about this issue at the Summit on IP and New Media, held at Denver University in Denver USA. My research was later published as an article in the Denver University Law Review.