The UK's Government Communications Headquarters (GCHQ) spy agency has been exposed as scanning entire countries for server weaknesses so it could find exploit vulnerable ports.
According to press reports, it does this using a tool called 'Hacienda' (Spanish for 'estate').
The accusations came out in German newspaper Heise.
"In 2009, the British spy agency GCHQ made port scans a 'standard tool' to be applied against entire nations," Heise reports.
"Twenty-seven countries are listed as targets of the Hacienda."
Hacienda has the ability to carry out a so-called "port scan" of all of the servers in a country to provide information on user endpoints and scan for potential vulnerabilities.
Targeted services include SSH, HTTP and FTP, among others, claim Heise's sources.
The ability to port scan is not new - but such widespread and indiscriminate use by government spies, spanning 27 sovereign nations scanned even before 2009, is a new and shocking development in the on-going post-Snowden world..
For its part, the government's signals surveillance agency declined to affirm or deny Heise's sensational revelations.
"It is a longstanding policy that we do not comment on intelligence matters," said a GCHQ statement issued to the press.
"All of GCHQ's work is carried out in accordance with a strict legal and policy framework, which ensures that our activities are authorised, necessary and proportionate, and that there is rigorous oversight, including from the Secretary of State, the Interception of Communications and Intelligence Services Commissioners and the Parliamentary Intelligence and Security Committee.
"All our operational processes rigorously support this position."