honor among thieves 小偷也有自己的行规(有其共同遵守的行为准则)
(as) thick as thieves 【口】 非常亲密
All are not thieves that dogs bark at. 【谚】 被狗吠的不见得都是小偷
Set a thief to catch a thief. 【谚】 以贼擒贼(以毒攻毒)
When thieves fall out, honest men come by their own. 【谚】 坏人内讧,好人得利.