The title of this article says it all: The American Civil Liberties Union disclosed yesterday that it filed a lawsuit three weeks ago challenging the FBI's methods of obtaining many business records, but the group was barred from revealing even the existence of the case until now. The lawsuit was filed April 6 in U.S. District Court in Manhattan, but the case was kept under seal to avoid violating secrecy rules contained in the USA Patriot Act, the ACLU said. The group was allowed to release a redacted version of the lawsuit after weeks of negotiations with the government.