An agitated young man disrupted railway service and frightened passengers last week in a profanity laced tirade that forced MTR officials to call the police.In an 86-second viral video, the man in his 20s was shown using his body to stop the platform screen doors and train doors from closing at Lok Fu station. The man shouted vulgar words in Cantonese, while on a train on the Kwun Tong Line.Other passengers were heard on the video contacting the train driver for help.When a male MTR station…