I've noticed a new kind of spam getting through my blog's spam filters lately. I've dubbed it "praise spam". You see, whenever you leave a comment, you can optionally leave the URL to your website. This serves several purposes. Sometimes, as I'm reading a discussion on a blog, one commenter will strike me as particularly funny or insightful, and it's nice to be able to click a link to go see their blog and read more about that person. It is also provides a benefit to commenting, an external link back to your website, thus motivating someone that wouldn't comment to enter in the discussion. Some spam bots have figured out a way to abuse this back-linking system. For instance, if someone leaves a comment that is...
BUY VIAGRA! big penis low interest mortgage penis v1agr@ mortgage mortgage. GO HERE: http://mortgagepenislarge.co.cn/
...the owner of the blog is obviously going to delete it. (and believe me there are still plenty of comments like this)
But if you were a clever spammer, and there are many out there, you'd leave a comment that really could have been made by a human. And if you're really smart, you'll make it a comment that the owner of the blog won't want to take down. Like so:
This is a really great post! Thanks so much for this. BTW, I love your blog.
And then you stick your url into the optional url field, so that when your comment is posted, there's a link back to your nefarious site. There is one plastic surgery site in Turkey that's been doing this a lot to my blog. The name he leaves is "Estetik", and, due to his spamming efforts, he's the number one google hit for that word. Obviously I won't provide a link here, but you can go see.
What I normally do when I'm not sure if the commenter is human or not is remove the url value from the comment and leave the ambiguous praise.
For instance, on my previous post, I received the comment:
nice post on Manualists! I can now go to sleep in peace! No honestly- great post, thanks.
Note that the comment matched the exact capitalization of the title of the post. To the programmer in me, comment really reeks of an automated template comment. The url attached to it is for an ad-laden English blog about Catalunya, Spain. That coincidence might lead one to think the poster was human, but the fact that the IP address of the poster is from Ebay's offices in San Jose, California, is a point in the "bot" column. We'll see. If the commenter would like to return and defend his humanity, then great.