On 28 November 2010, WikiLeaks began publishing classified U.S. diplomatic cables, including a reference to Surveillance Detection Units operating from American embassies. The cables described U.S. embassy personnel conducting secret surveillance of citizens and other inhabitants in host countries. The disclosure raised a fundamental accountability problem: covert monitoring was being carried out under diplomatic cover, with the source providing no evidence that affected people, parliaments, or courts had been informed or given an effective means to challenge the activity.
The same leak documented wider U.S. pressure for access to European communications and financial data. A December 2009 Berlin cable, 09BERLIN1528, said Interior Minister Thomas de Maizière overruled Justice Minister Sabine Leutheusser-Schnarrenberger and abstained from a 30 November vote on an interim U.S.–EU Terrorist Finance Tracking Program agreement. The source does not report prosecutions or a definitive court ruling against the surveillance units, but the disclosures exposed the secrecy surrounding diplomatic monitoring and transatlantic data-sharing arrangements, prompting renewed public and governmental scrutiny of privacy safeguards.