First, you need to sign up for a free account to use it, with an email address and a password. But they don't verify the email address at all! So it is in fact completely anonymous, there is just a pointless speedbump in the way. I guess it is for spamming rather than kiddie porn panic?
It makes you log in with your made-up email address and password before passing any packets, and they set the login page to not remember either the address or password even if your browser is set to remember such things. And, it has a very short time-out.
So, you open up yor mail reader, it tries to get mail, you are redirected to a "welcome" page in the web browser (not even the login page!) where you have to do a fucking lot of typing... And then maybe you can dow nload your mail. Maybe. By the time you are on the return train, you will have to do this login dance again.
Whoever is responsible for this stunning design failure deserves continuous cockpunches.
This message brought to you by the just-slightly-lesser failure that is the AT&T network.