Who will be watched and by whom? The test phase will take place at Berlin’s Südkreuz train station. It will include only selected participants and be conducted by the German federal police, Federal Criminal Police Office and the Interior Ministry in conjunction with Deutsche Bahn, the station operator. More than 250 people have volunteered as test subjects. They submitted their names and two photos of their faces, which have been saved in a database so cameras can compare them to surveillance footage.