I won't use any service that requires any form of identification. Not that I think my identity is hidden -- the NSA probably is reading this right now -- but as a matter of principle. I shouldn't have to identify myself to express an opinion. It's like requiring writers to put their real names on their books before they are allowed to publish. Writers have been publishing anonymously or using pen names for centuries. Readers don't need to know their identities to appreciate what they have published in their books. Similarly, nobody needs to know who I am to judge whether or not my posts are interesting and entertaining.