The University of California is flexing its muscles to protest the increased cost for access to the Nature Publishing Group's journals and magazines. In a letter to the UC faculty [pdf], the California Digital Library says that NPG is increasing the cost of access by 400 percent, which translate to a more than $1 million increase per year. "While Nature and other NPG publications are among the most prestigious of academic journals, such a price increase is of unprecedented magnitude," the letter says.