I’ve now enabled a basic captcha system provided by a Movabletype plugin called SCode. In order to make it work I had to do a couple of things that are not mentioned in the official installation instructions:
1. make the mt-scode.cgi CGI script executable:
# chmod a+x mt-scode.cgi
2. make sure that SCode is enabled and configured both on a MT global level and on a per-weblog basis
3. Correct a bug in SCode.pl:
replace security code you see here\” src=\”$path/plugins/SCode/mt-scode.cgi by security code you see here\” src=\”$path”.”plugins/SCode/mt-scode.cgi
#3 is not essential, but a bug nonetheless.
Hopefully, the comment spam problem is now solved for a while by enabling this plugin. Trackback spamming is still possible, though.
Please contact me if you are visually impaired and would like to post a comment on this blog. Ideally, the captcha image should also be available as a sound file/stream, but I haven’t found the time yet to implement sth like this.