The American Civil Liberties Union has dropped its lawsuit against the TSA after the agency issued new guidelines limiting the scope of airport searches. "Screening may not be conducted to detect evidence of crimes unrelated to transportation security," according to the new rules. The crackdown comes after a GOP political aide recorded a half-hour confrontation with TSA officers and local police who found him carrying $4,700 in cash from a political fundraiser. A TSA spokeswoman declined to release the "internal directives" when questioned by reporters, but she did say that cash was singled out in the new policy. "Currency alone is not a threat, and TSA does not restrict the amount of currency a traveler may carry through the checkpoint," she said.