IN THE PAST FEW weeks there have been two significant disclosures concerning the rules that govern domestic spying, just as the House and the Senate are preparing to reconcile versions of a bill to reauthorize key provisions of the USA Patriot Act. The first was a release by the FBI of internal reports docu- menting violations of the rules of domestic surveillance in national security cases. The second was a story by Post staff writer Barton Gellman revealing that the number of "national security letters" -- a kind of administrative subpoena used by the FBI to obtain normally private records -- has exploded since the passage of the Patriot Act and now reaches 30,000 per year. These reports open a timely window onto the question that animates the debate over the Patriot Act: How responsibly is the government using its spying powers? Though they don't provide a complete answer, the new disclosures are troubling.

The surveillance reports, generated by the FBI general counsel's office and released under a Freedom of Information Act lawsuit, are heavily redacted. Still, they show that there have been at least 13 cases between 2002 and 2004 of violations serious enough that the FBI itself determined they must be reported to an executive branch agency called the Intelligence Oversight Board. Moreover, the case numbers on the released documents suggest that there were hundreds of potential violations examined by the bureau during that period. This is cause for concern. Errors happen in any complex bureaucracy, and it isn't clear that these are serious ones in civil liberties terms rather than mere technical mistakes. Moreover, in some sense, the existence of these documents is encouraging. They are the results of the bureau's internal reporting of errors, and the general counsel's office appears to be giving conscientious review to those cases that come its way -- at least in cases the bureau chose to release. In other words, this limited cache of documents could reflect dangerous carelessness in the field or a good system for catching mistakes -- or even both at the same time.

Similarly, the data on national security letters are worrisome, but it's not quite clear what they mean. These demands for records, which can include such things as phone and bank transactions and Internet subscriber data, get sent out on the bureau's own initiative under a very low standard and without the oversight by Justice Department prosecutors that takes place in a regular grand jury investigation. Policy changes since Sept. 11, 2001, have allowed greater retention and dissemination of information that gets collected -- including, disturbingly, to governmental and private parties outside the FBI. While bureau officials will not discuss the number of national security letters, they do say that for about 10 out of every 11 people whose records are collected, the information is telephone subscriber data that are already in the public record. Clearly, however, information about innocent people is being swept up, retained and mined. All of this creates the potential for abuse.

More information is needed. The Justice Department's inspector general, Glenn A. Fine, ought to investigate, and report to Congress and the public. And as conferees put the final touches on the reauthorization bill, they should write into the law requirements that the FBI more fully disclose whom it has targeted in its domestic spying operations, what information it is gathering and what use is being made of it.