part of
http://bugs.splitbrain.org/?do=details&id=1014
robots.txt in the DokuWiki take up with the most well-known harmful Bots and email (Spamer) collecting tanks
User-agent: Titan
Disallow: /
User-agent: EmailCollector
Disallow: /
User-agent: EmailSiphon
Disallow: /
User-agent: EmailWolf
Disallow: /
User-agent: ExtractorPro
Disallow: /
.... and more