When President Obama took office in 2009, he promised an “unprecedented level of openness in government.” In a memo issued the day after his inauguration, he wrote, “The government should not keep information confidential merely because public officials might be embarrassed by disclosure, because errors and failures might be revealed, or because of speculative or abstract fears.”

In the latest reminder that the Obama administration has failed to live up to that promise, the Justice Department last week won its fight to keep secret a memo that outlines the supposed legal authority for the Federal Bureau of Investigation to collect Americans’ telephone and financial records without a subpoena or court order.

The memo, issued in 2010 by the department’s Office of Legal Counsel, approved of the bureau’s use of what are known as exigent letters to obtain phone records without any legal process, and in the absence of any emergency. From 2003 to 2006, the bureau used these letters to obtain phone records for more than 3,500 accounts.

Last Friday, a unanimous panel of the United States Court of Appeals for the District of Columbia Circuit ruled that the memo could be kept secret from the public because it was the product of internal agency deliberations and had not been formally adopted as department policy. (The F.B.I. has said it no longer uses exigent letters.)