A federal judge this week struck down a controversial set of laws allowing the Federal Bureau of Investigation to seek people's records without a court's approval, saying the strict secrecy orders demanded by the laws are not constitutional.

Judge Susan Illston, of U.S. District Court for the Northern District of California, said the laws, which underlie a tool known as a "national security letter," violate the First Amendment and the separation of powers principles. In her order, Judge Illston ordered the government...