According to unnamed German security officials, German chancellor Angela Merkel's mobile was wire-tapped by at least five foreign intelligence agencies.

When it became known that the US had bugged her phone, it set of an international diplomatic incident that resulted in President Obama promising to lay off. However, the US was not the only one bugging her. Her phone was also bugged by the Russians, Chinese, North Koreans and Britain's GCHQ.

It is not clear as to how she was bugged, be it some form of malware or over the air interception.

Berlin is still a hot spot for spy recruiting. Foreign agents are constantly trying to recruit German politicians, civil servants, military personnel and scientists as agents.