If I open a paid Wordpress.com account using my real e-mail address and a credit card registered to my home, and post a $10 reward for revealing my identity, the fact that I strongly doubt anyone will claim the reward is not proof of Wordpress.com's perfect safeguarding of my identity, just that their systems are secure enough to not be trivially hackable and that nobody cared enough to find a way to obtain a court order to compel WP.com to hand over my info.