"Even in these difficult times data protection should not be neglected. For this reason I would like to point out that the use of WhatsApp by a federal agency is out of the question", Kelber said in an email published by the German digital rights blog, Netzpolitik.
He warned that, although Facebook could not read encrypted messages, the application was providing it with other "metadata" like the IP address, location and the mobile operating system that could be used to piece together the user's profile.
WhatsApp Messenger is an American freeware, cross-platform messaging service owned by Facebook that allows users to send text and voice messages, make voice and video calls, as well as share images, documents, user locations, and other forms of media.