Where did comments come from?

I have never enabled comments or subscribers on my site. Yet, last week I noticed that I’ve been getting occasional comments anyway. As far as I can tell none were visible to the public, just to me. Some are spam, others are obscene but oddly friendly. Where could they have come from? As far as I can tell none were visible to the public, just to me.

The page I need help with: [log in to see the link]