If you comment on this blog, your email information (or facebook or twitter login information) is necessary to do so. However, this will not be visible to the public. When you comment, your name will appear to the public, with a link to your website if applicable. If your email is associated with a gravatar, or if you login with facebook or twitter, your picture will also show next to your comment.
If you subscribe to comments, or if you subscribe to the blog via email, your email will be used to send you the comments or blog, as you requested. This is an opt-in service, and your email will not be used unless you’ve authorized it.