National-Security Surveillance Plummeted Amid Pandemic and Russia Inquiry Fallout

The judge in that case said the F.B.I. had reported to the court that its internal oversight and compliance audits in 2020 had found several problems, mostly in 2019. Among them were instances in which the F.B.I. system had a previewing pane that had automatically displayed to analysts portions of results of queries of the warrantless surveillance repository, including some searches undertaken for criminal investigations into health care fraud, violent gangs, public corruption and bribery.

Since a 2018 change to the law, the F.B.I. is supposed to obtain a court order before viewing such material about an American for ordinary criminal investigations, but it had not sought such an order through the end of 2020.

A senior F.B.I. official said most of the problematic incidents were attributable to the previewing pane issue, and none were deemed intentional or malicious violations of the rules. The F.B.I. has since changed its systems to get rid of the viewing pane and added training — steps that prompted the FISA judge to say the program could continue.

The newly disclosed report also shed new light on the F.B.I.’s use of its power to obtain business records in national-security investigations under a law known as Section 215 of the Patriot Act. Congress allowed that law to expire on March 15, 2020, amid chaotic messaging from then-President Donald J. Trump as he stoked grievances over the Russia investigation, and lawmakers have not reauthorized it.

There is a catch, however, that may be relieving some of the pressure over the continued lapse of that authority. Because of the way the law was written, the F.B.I. may still obtain Section 215 orders for investigations that were open before March 15, 2020, or for new investigations into activity that took place before that date.

It had not been clear to what extent the bureau has been using that residual authority. The new report said that in all of 2020, it obtained 28 such orders covering 25 targets, down from 61 orders covering 53 targets in 2019.

In the briefing with reporters, a senior Justice Department official said that about 20 of those 28 orders were obtained after March 15, 2020, using the residual authority to issue them for pre-existing matters.