The NSA and GCHQ have attempted to break the privacy protections of the Tor anonymity network, according to a series of documents published in The Guardian today. The documents describe the efforts of the NSA to de-anonymize Tor users by compromising their computers and Tor software with viruses. The NSA also relies on Doubleclick advertising cookies to identify Tor users. Despite their efforts, the documents reveal that the intelligence community has had limited success compromising the Tor network. One presentation, titled "Tor Stinks," concludes that they will "never be able to de-anonymize all Tor users all the time." In May 2013, EPIC filed a FOIA request seeking evidence of government interference with the Tor network. In 2000, EPIC had also filed a complaint with the FTC about Doubleclick's efforts to merge users' browsing activity with personally identifying information. And in 2007, EPIC objected to Google's acquisition of Doubleclick, warning that it would place at risk the privacy of Internet users. For more information, see EPIC v. BBG; EPIC: Privacy? Google/Doubleclick Merger.