[JURIST] The US Supreme Court [official website] opened its 2011 term Monday with oral arguments [day call, PDF] in two cases. In Reynolds v. United States [transcript, PDF; JURIST report], the court heard arguments on the retroactive application of the Sex Offender Registration and Notification Act (SORNA) [final guidelines, PDF], which requires convicted sex offenders to register. The attorney general determined in 2007 that all states would have to follow the federal rule to keep registration current. Billy Joe Reynolds…