There are some blogs where you have to jump through a series of hoops in order to be able to leave a comment on their posts.
The information required by this kind of blog is sometimes:
(a) Your Name
(b) Your e-mail
(c) Your website
and, in addition to that, you have to enter your WordPress.Com password in a seperate window that pops up.
This process can become frustrating and exasperating.
My own blog allows anybody to comment without all the extra steps.
I wish people who have (We need to know everything before we let you post comments) kinds of blogs had the same or a similar setup as my own.