BOSTON (Reuters) - If U.S. officials overhear talk of a planned murder or rape while eavesdropping on a telephone call under President George W. Bush's domestic spying program, what can they do -- within the law -- to stop it? "We don't know," said Harvard law professor and celebrated defense lawyer Alan M. Dershowitz. "Plainly we would not want them to ignore it" but no laws have been written to govern how the information can be used in court, he said. "We wouldn't even know where to look to find the law because there is no law," Dershowitz, one of...