Reuters: Seven environmental groups filed a lawsuit on Thursday challenging safety rules issued earlier this month for trains carrying oil, arguing the regulations are too weak to protect the public. The groups, including the Sierra Club and Center for Biological Diversity, charge that the rules, issued on May 1, will allow industry to continue to use "unsafe tank cars" for up to 10 years and fail to set adequate speed limits for oil trains. "Were suing the administration because these rules wont protect...