Deutsche Bahn is in deep trouble. Not only has the state-owned operator had to postpone a recent planned part-privatisation because of the financial crisis. Now it is also accused of spying on its own staff.
"I am so angry, I still can't believe that they were spying on their workers for so many years," says one employee, who does not want to be identified, as he nervously looks around at the crowd outside the underground station at Potsdamer Platz.
Although people's faces were concealed by large woollen hats and scarves, it seemed as if he was scared that someone would recognise him.