Re: This story brought to you by the Union and anti-IBM crowd
It's classic penny-wise, pound-foolish behavior.
* A $20 debt from an inactive account certainly costs more for them to collect (in AR staff time) than the amount of the debt.
* It generates ill will within a class (technology professionals) it is actively hiring from.
* It looks bad for a technology firm to say "gee whiz, we don't know how we overpaid you. Our record keeping and accounts payable need some better integration.
But aside from all of that... Aside from matters of perception and economic benefit, common sense and human decency dictate that you do not do this.