Sam Sethi, a former blogger for the UK edition of TechCrunch, Michael Arrington's tech blog, had tried to keep things cordial with his former boss. The site he started, BlogNation, is the global equivalent of TechCrunch, but direct competition was avoided by not covering American startups. No longer. Sethi is taking the fight stateside with BlogNation USA. TechCrunch UK, meanwhile, remains defunct despite Arrington's planned June 1 relaunch.