The Detroit Free Press reports that the Detroit Federation of Teachers union is threatening to have up to 70 teachers fired for not paying forced union dues.  A school district error is mainly responsible for the mix up. 

Yet, because of the clerical error, union official Mark O’Keefe stated that the "fair" thing to do would be to fire the teachers who fail to pay the full union dues.

No, Mark.  The "fair" thing to do is to not require teachers to pay ANY union dues as a condition of teaching Detroit’s schoolchildren.