1. 如果律师成为客户的被告但是不能用客户的信息自我辩护,那么没有人要去做律师了。这样就限制了社会的法律服务。所以这是一个公共政策的理由,中文里面叫做为了公序良俗(公共秩序和善良民俗)。
Wikiepedia: Lawyers may disclose confidential information relating to the retainer where they are reasonably seeking to collect payment for services rendered. This is justified on policy grounds. If lawyers were unable to disclose such information, many would undertake legal work only where payment is made in advance. This would arguably adversely affect the public's access to justice.
2. Public Policy翻译为公序良俗的根据