The Evolution of a "Comments" Policy

Google and Blogger seem, at the moment, capable of fending off spammers from the "comments" option. Still, every once in a while I receive something that gets me wondering. I just deleted a comment from my last entry. My impression was, the commenter visited the site, hit "comment", right-clicked "paste", then hit "publish". Too "personal" to qualify for "spam", but too impersonal to qualify as a comment = deleted comment.