It's much the same in the Postal Service. The unions are the biggest reason why it's bankrupt.
Case in point:
I work there part time. If I work even a single minute over 40 hours, the union dictates that the Post Office must pay the career employees (full time folks) overtime pay for every minute of overtime that I work.
That's not the half of it. Say we have two employees...A and B. If employee B helps out employee A, even if A asked for the help, a "grievance" can be filed and ANYONE who is trained to do the same job that the employee A is trained to do will get paid the amount of hours that the employee B worked while helping employee A. (Also, employee A who asked for help can also file a "grievance" so that he/she is paid for employee B's "helping" hours as well)
The irony abounds in the Postal Service. It's sad that the employees there do not see how it's dragging the system down, yet every day I hear them moan and bitch about how USPS is laying people off and there's a hiring freeze on.