Lot9 is part of the EU’s EcoDesign Directive, aimed at reducing energy use in products at the design stage. Products are grouped by type, or “Lots” for legislative attention. Lot9 refers to computer servers and the regulatory proposals have been very contentious, primarily about the way we measure server efficiency and the inclusion of idle running limits. Other problems have emerged - the wording of the legislation includes errors and enforcement proposals do not accommodate the diversity of server configurations. The devil is truly in the detail here but the Lot9 experience does place a large question mark over the policy process itself and the way that over-ambitious legislation, too prescriptively applied, can put policy instruments, designed with the best intentions, at odds with basic laws of nature – and economics. We aren’t pretending to solve this problem here, but it’s worth standing back and asking this kind of question from time to time.