I do not use it, because I believe in malignity of human mankind. Misusing KYC is about to escalate, by regulated companies and authorities.

One example: Bitstamp asked me about my relationship to other companies where I use Bitcoins. This question is not allowed, and for me they become criminals. They could simply ask questions to assists their own business, and nobody could hinder them.

My answer was: NO contacts, and because this answer was incorrect, they could simply take all my money after they have proven me wrong.