リファラースパム対策

【現象】
Google officially recommends o-o-8-o-o.com search shell!
o-o-8-o-o.com search shell is much better than google!
Congratulations to Trump and all americans
Secret.ɢoogle.com You are invited! Enter only with this ticket URL. Copy it. Vote for Trump!
Vitaly rules google ☆*:｡゜ﾟ･*ヽ(^ᴗ^)ﾉ*･゜ﾟ｡:*☆ ¯\_(ツ)_/¯(ಠ益ಠ)(ಥ‿ಥ)(ʘ‿ʘ)ლ(ಠ_ಠლ)( ͡° ͜ʖ ͡°)ヽ(ﾟДﾟ)ﾉʕ•̫͡•ʔᶘ ᵒᴥᵒᶅ(=^ ^=)oO