I just got a piece of advertising email that I thought might be spam because I'd never heard of the sender, let alone signed up to get messages from them, so I scrolled to the bottom of the message to see where they got my name. It said:"Please do not reply to this email.
You opted to receive Lycos Special Offers when you registered on a Terra Lycos Network website. You can change your registration and email subscription information at:
"on a Terra Lycos Network website" huh. Which one??? I don't remember everywhere I've registered over the years and anyway my relationship was with that particular site - not its parent company (which I might not have even known was its parent company - do you know all the sites Terra Lycos owns off the top of your head?)
It gets worse. So I clicked on the link to see which site, and guess what? It doesn't tell you. In fact you can't change your settings or unsubscribe until you give them your password. I'm supposed to remember a password for a site, when I don't even know which site it is?
Lesson -- don't rent lists from Terra Lycos because they are abusing permission and make unsubscribing unusually difficult.