Defeating manual spam, or damn dastardly conniving commenters!

I'm not especially keen on meta-blog posts, but the issue came up in email recently and I've this penchant for expounding at some length on interesting subjects, even in the least suitable medium, target audience: one. Fortunately I have a blog.

Not so fortunately, manually entered spam has been an issue. When you optimize for humans you regrettably include manual spammers.

Such spam is surprisingly devious, but here are some common characteristics:

  • Complimentary. "Wow this is a great post!"
  • Relative. "I don't like spam."
  • Unconstructive. Adds nothing of value.
  • Disingenuous. "I appreciate it because…"
  • Erroneous. "…this should keep spam out of my email inbox."

See! Manual spam is recognizably crude.

ego spam

Of course the payload is the link, and they aren't all blatant advertisements, but even sites which might appear legit may advertise themselves unscrupulously. As expected they will lack real content.

Here with BlogEngine.NET the payload is put in the website field and not the body (the name field is the link text). Neither asking for your name nor indicating the website field is ignored by search engines made a difference.

Akismet did however, and thus far I've had zero false positives, only false negatives. Some have been crafted so cleverly as to be very close, but after investigating I've concurred. If Akismet marks a unique (but crude) comment as spam I expect the link to be unsatisfactory given that it's the defining constant.

My recent addition of reCaptcha seems to have made the largest difference. Most likely because there's now some difficulty involved. I actually feel pretty good about this because the duality of distinguishing computers from humans while simultaneously solving complex problems that computers do poorly absolutely fascinates me. Given that solving my captcha is now no longer a technical waste of time, I know some readers will begin to feel that it isn't as well.