[Traveler59]

1. Sign them up for every spam mailing list and objectionable organization (like, say, NAMBLA) you can find. Their mailbox will overflow in no time and they might even get terminated depending on how thorough background checks are.

This actually happened to a notorious email spammer. The folks a slashdot.com got his postal address and posted it with the instructions that all of their on-line readers go to the local library and/or bookstore and remove the prepaid postage flyers from magazines and send them off with the spammers address. At the height of the email spammer vs. postal spammers war, the email spammer was getting 5 to 15 BAGS of mail a day. He pleaded with the USPS to stop, but they are required by law to deliver all mail. I'm not sure what the end result was, except the email spammer was doing the usual litigation threats if he ever found out who did it.

[Spktyr]

Exactly what I had in mind. It’s more effective and longer lasting than a short-lived winter protest and requires little effort on the part of those the target has offended.