Why would they have a server farm on foreign soil?
Frankfurt used as remote hacking base for the CIA: WikiLeaks
(excerpt)
WikiLeaks documents reveal CIA agents were given cover identities and diplomatic passports to enter the country. The base was used to develop hacking tools as part of the CIA's massive digital arsenal.
*snip*
The consulate was the focus of a German investigation into US intelligence capabilities following the 2013 revelation that NSA agents had tapped Chancellor Angela Merkel's phone.
German daily "Süddeutsche Zeitung" reported the building was known to be home to a vast network of intelligence personnel including CIA agents, NSA spies, military secret service personnel, Department of Homeland Security employees and Secret Service employees. It reported the Americans had also established a dense network of outposts and shell companies in Frankfurt.
Why indeed.