Neil Turner's Blog

Blogging about technology and randomness since 2002

Typepad’s answer to comment spam

Paul Lindner at the Everything TypePad blog has posted how TypePad has tackled the problem of comment spam. As far is I can tell, when you post a message to a TypePad blog, TypePad checks your machine to see if it is running an open proxy server. If you aren’t, your comment is posted as normal, otherwise you get an error. Apparently, this blocked 20 000 spam comments on the first day of implementation alone.
So what about those of us who aren’t TypePadistas? There are rumoured to be around 1.5 million machines with open proxies (often caused by backdoor trojans), so maintaining a list will be stupidly complex. OPM has a list of known open proxies and is used by systems like SpamAssassin when an email is received, so perhaps a modified mt-comments.cgi could query this and deny comments. Or the script could simply do what TypePad does and probe the machine for an open port, although my experience of logging on to IRC servers with SOCKS probing means that this may slow down the login process considerably if the machine has a stealthing firewall.
I’m sending this to the LazyWeb, just in case someone out there can think up a technical solution. Implementing something like this could really make a difference in the fight against comment spam.

Comments are closed.