Legit Comments From Spammers?

Things used to be so simple.  If I got a comment that was in Russian, I would mark it as spam.  If I got a comment promising me “extra inches” or “wealth”, I would mark it as spam.  If I got a nonsensical comment, I would look at the URL and, sure enough, spammy link goes in the spam bin.  Truthfully, I’d rarely mark these as spam myself.  Akismet takes care of this for me most of the time.  You get the picture, though.

Recently, though, the line between spam and normal comment has blurred.  At first, it was valid comments that appeared to somehow hijack CommentLuv.  Upon further investigation, this turned out to be spammers copying previous comments and using them for their own comments.  (Replacing the links, of course, to be their own spammy links.)  That was annoying, but once I was on to their trick they couldn’t get by me.

Now, though, the spammers have me in a quandary.  And I’m not even sure it’s spammers I’m dealing with.  You see, I’ve recently had a few comments on my blog posts that are completely on topic (referencing specific themes of my post or my kids’ pseudonyms), use proper grammar and spelling, and are (as far as I can tell) 100% original.  No copying bits and pieces to form a Franken-comment here.  This wouldn’t be a problem except that the links given trigger my internal spam-alert sirens.

Is that comment really a valid one about my blog post even if the site linked to reeks of spam?  Should I allow it to remain on my blog?  Should I take it down?  Should I remove the URL so that the comment remains but the link doesn’t?  So far, I’ve been removing them entirely, but I’m afraid of removing a valid comment from someone whose URL just looks “different.”

Have you encountered comments like this?  If so, what did you do with them?