Why is the US on the defensive?

Kenneth Bamberger and Deirdre Mulligan cited in The Privacy Advisor, March 24, 2014

The only reasonably thorough study comparing actual EU and U.S. privacy levels was conducted in 2006…. It’s about to be joined by Privacy on the Ground: Governance Choices and Corporate Practice in the U.S. and Europe, by Kenneth Bamberger and Deirdre Mulligan, who, after extensive study, also seem to believe it is not a foregone conclusion that the EU has the superior regime.