As most of you are aware of by now, Johnson celebrated a touchdown by mimicking shooting himself in the leg, a direct shot at Jets receiver Plaxico Burress. (Johnson has apologized to Burress for the incident.) He followed that up by mimicking a jet crash; it was his act of going to the ground for that portion of the celebration that drew the unsportsmanlike conduct flag.
As far as we are aware, this is the third time that Johnson has been fined in less than two years as a starting receiver. He was docked $10,000 for mimicking the Minutemen in a Week 3 loss to New England last year, and was fined a further $5,000 for the "Why So Serious?" celebration that made him quite famous in a win over Cincinnati. Johnson told reporters Monday that he didn't know falling to the ground in a celebration was against the rules, but that's exactly why he was flagged - and fined - in New England a year ago.
Three fines. $25,000. Whatever you think of Johnson after his latest on-field incident, his wallet is considerably lighter.