User-agent: Googlebot
Disallow:

User-agent: AdsBot-Google
Disallow:

User-agent: Googlebot-Image
Disallow:

User-agent: Yahoo-slurp
Disallow:

User-agent: Msnbot
Disallow:

User-agent: Twitterbot
Allow: /images

User-agent: DuckDuckBot
Disallow: