I don't like the idea of punshing someone just because a person put them on the ignore list.
Seems kind of silly to me.
People that need to ignore eachother on the forums do not do it nearly enough. I say we give them incentive to, by making it so that when they globally ignore them, reputation is deducted from that person, but given back if they choose to stop ignoring them. The amount deducted would depend on the person choosing to ignore's own reputation, so they wouldn't be able to make any accounts to troll.
It would also prevent further problems from occurring between those people.