Sign up for an account, if you want to:

No thanks.

claim your thoughts as your own....

That's okay, you can have them. Information is better when people don't try and control it :).

put a name to your words....

Why? Then the message is lost. Many will judge what you say based on their previous impression of you. They'll either blindly accept what you say as truth, or blindly disregard it.

take responsibility for your words....

I take just as much responsibility as you do. I don't have anymore privacy than you. I can be tracked just as easily. Responsbility is the same either way.

stop hiding behind the Anonymous Monk...

Just because someone doesn't sign up an account and state their life story on every website they visit doesn't mean they're hiding :).

Hey Brother Christian with your high and might errand,
Your actions speak so loud, I can't hear a word you're saying.
Bad Religion

There are also many good reasons why someone wouldn't want to sign up an account. Take a minute, I'm sure you can come up with a few.