User-agent: Google
Disallow:

User-agent: Googlebot
Disallow:

User-agent: Bingbot
Disallow:

User-agent: Slurp
Disallow:

User-agent: DuckDuckBot
Disallow:

User-agent: Baiduspider
Disallow:

User-agent: YandexBot
Disallow:

User-agent: Sogou
Disallow:

User-agent: Exabot
Disallow:

User-agent: facebook 
Disallow:

User-agent: facebookexternalhit/1.1
Disallow:

User-agent: ia_archiver
Disallow:

User-agent: MJ12bot
Disallow: /

User-agent: *
Disallow: /