A woman holds a flag with the logo of Germany's Verdi union as she attends a four-hour strike by security staff at Berlin's Tegel airport on January 7, 2019. - Hundreds of German passengers were facing travel upheaval with security staff at Berlin's two airports walking out in a pay dispute. The action was called by the powerful Verdi union that wants to see wages raised to 20 euros ($23) per hour for workers carrying out passenger, freight, personnel and goods checks at German airports. (Photo by Tobias SCHWARZ / AFP)