Yesterday, Lufthansa pilots carried out their 10th strike this year. Deutsche-Welle, Munich, Frankfurt and Dusseldorf were most affected by the strike. Earlier in the week, pilots held another strike that led to 1,350 flights being cancelled, which affected 150,000 travelers. The striking pilots that are demanding to have an early retirement age of 55.
See "Lufthansa Cancels Half of All Long-Haul Flights as Pilots Strike Again Over Retirement Benefits", Sneha Shankar, The International Business Times, December 4, 2014