With a tweet yesterday, an editor of Scientific Reports, one of Nature Publishing Group’s (NPG’s) open-access journals, has resigned in a very public protest of NPG’s recent decision to allow authors to pay money to expedite peer review of their submitted papers. “My objections are that it sets up a two-tiered system and instead of the best science being published in a timely fashion it will further shift the balance to well-funded labs and groups,” Mark Maslin, a biogeographer at University College London, tells ScienceInsider.