I have a stats counter in www.StatCounter.com - "Free Web Tracker & Counter", I got an email about an upgrade they did. I clicked the link and pressed ok after checking a checkbox, a millisecond after clicking I saw that I was deleting my account. A small mail to the webmaster produced this answer:

Hi Yosi,

Wait a second - did you not have to tick a box saying "I confirm that I want my account closed" ? With big red letters saying "warning"!

And you ticked it? What else can I do to stop people from automatically closing their accounts? (you're not the first!)