Yesterday’s xkcd is a good one.
@simonwoods I think it's missing the "Do you really want to unsubscribe? we have cookies" (click the "yes, I don't like cookies" button which is white on a white background) then the next popup comes up "This is your last chance to stay subscribed and get cookies" (spend five minutes working out which button is the unsubscribe button...turns out it's niether button, but there is some text at the bottom of the page which unsubscribes you...and subscribes you to another list)