Germany’s top intelligence agency handed over details related to German citizen metadata just in order to obtain a copy of the National Security Agency’s XKeyscore surveillance software. The software is powerful enough to be able to pull, including emails, chats, social media interactions, and even browsing histories all in real-time without bothering the need of any warrant. In return, the German intelligence agency promised to share their citizens metadata. The deal was signed in 2011 after two years long negotiation with the U.S., the German agency signed an agreement.
Source: https://thehackernews.com/2015/08/german-spies-nsa-xkeyscore.html