The New York Times is reporting that Australia's NSA counterpart, the Australian Signals Directorate (ASD), monitored a US-based law firm while that firm was representing Indonesia in trade disputes with the US government. The eavesdropping occurred with the NSA's approval, and ASD apparently offered to share the information with the NSA.

These revelations are part of yet another set of documents provided by former NSA contractor Edward Snowden.

The New York Times wrote:

The Australians told officials at an NSA liaison office in Canberra, Australia, that 'information covered by attorney-client privilege may be included' in the intelligence gathering, according to the [February 2013] document, a monthly bulletin from the Canberra office. The law firm was not identified, but Mayer Brown, a Chicago-based firm with a global practice, was then advising the Indonesian government on trade issues. On behalf of the Australians, the liaison officials asked the NSA general counsel’s office for guidance about the spying. The bulletin notes only that the counsel’s office 'provided clear guidance' and that the Australian agency “has been able to continue to cover the talks, providing highly useful intelligence for interested US customers.”

The “US customers” have not been identified, but the quote is a reminder that the NSA engages in economic espionage, using spy tactics to learn about trade deals. The US government has forcefully denied that it passes any information that it receives on to US businesses, however, as China's government has been accused of doing for its business sector.

The news is also worrying for American law firms. If a US-based firm is representing a non-US client, the conversations between the two parties do not get special protections from NSA surveillance. The NSA is required to minimize the amount of information it gathers on American lawyers with foreign clients by scrubbing US identities or redacting information unnecessary to understanding the surveillance. “An NSA spokeswoman said the agency’s Office of the General Counsel was consulted when issues of potential attorney-client privilege arose and could recommend steps to protect such information,” the New York Times wrote.

In 2012, the American Bar Association revised its rules to require lawyers to “make reasonable efforts” to protect their clients' information from hacking and spying. Update: The ABA has responded to the news with a statement saying, "Although all the facts are not yet known, the American Bar Association is concerned about and will monitor reports of government surveillance of American lawyers' communications with their overseas clients." The ABA also sent a letter to the NSA on Feb. 20, expressing its concerns.

The Times also noted that the leaked documents reveal a strong collaboration between the US and Australia in trying to break encryption, especially with respect to communications from China and Indonesia. The US and Australia also “secretly share broad access to the Indonesian telecommunications system," the Times reports.