I've been having a bit of a spam problem on this blog. I really didn't want to do a captcha when I set it up, and I still don't. Captchas are always too cumbersome, if they're effective at all. Often they're more obtrusive to humans than they are to bots. Even good captcha can often be farmed out to humans after a trivial amount of reverse engineering. It can be very cost-effective to do this.

I think RBLs will be a little more effective for my use case, and be completely unobtrusive to most users. And it only took five lines of code:

#
# Check for spam on the Usenix RBL
#
my @ipa = split('\.', $ENV{'REMOTE_ADDR'});
my @ipa_rev = reverse(@ipa);
my $dnsbl_host = join('.', @ipa_rev) . ".all.s5h.net";
if (gethostbyname("$dnsbl_host")) {
        $COMMENT = "/srv/ephemeris/comments.spam/"
}

So it still saves the comment, but in a quarantine folder that doesn't get built with the rest of the site HTML. I might check it sometimes, maybe never. The spammer does not get notified that their comment was quarantined. So if you comment something and it never shows up, you can email me and I'll check it out. You might need to get your IP cleared over here (click the "rblremove" link -- don't refresh it too many times). However, you may have been listed because you have some malware on your computer or network that's part of a botnet.

Hey, spammers, if you're reading this, why do you only spam my Birthday Post?

Tags: blogging, internet, meta, spam, spam, spam, spam, spam | No comments