sister wives says four wives and 16 children is none of the government s business. their new lawsuit tests this question. is polygamy somehow protected by a constitutional right to privacy? plus late word the government s credit rating could be downgraded because of the stalemate in negotiations over spending cuts and raising the debt ceiling. that warning from moody s came hours after the fed chairman gave his take on the consequences of not letting the government borrow more money. failure to do that would certainly throw the financial system into enormous disarray and have major impacts on the global economy. but up first tonight, riveting and exclusive cnn images from the battlefield in libya. new u.s. intelligence assessments show cracks in the regime that suggest moammar gadhafi might finally be ready to discuss an exit strategy. well, perhaps. but our ben wedeman and his crew saw a short time ago an effort by pro-gadhafi forces to retake the town 60 miles south o