Unsubscribed Contacts - Automatically Tagged under contact profile

I would like to see an automatic "tag" placed on the contacts that unsubscribe to emails so that it can easily be searched in the contacts "FILTER" feature. Now you have to go to reporting, search unsubscribed contacts, go to the contacts and place your own tag manually.  This is just another step for the agents to have to do. This would be an easy implementation feature upon them clicking the unsubscribe link. Thanks!