neilio:

Protip: Whenever you need to give up your address (for a magazine subscription, contest form, etc.), add “c/o [Name of magazine/contest/etc.]” to the address field, so you can track which jerks end up selling your information even after you’ve specifically opted out of 3rd party referrals.

Example: this lovely plea for donations from the CNIB I received today, which very clearly originated from the Macworld subscriber database.