Despite a powerful last-minute lobbying blitz, the Department of Justice has apparently failed in its bid to block a new law that will prohibit federal prosecutors from talking to potential witnesses or defendants without notifying their lawyers.

The law, known as the McDade amendment for retired veteran GOP House member Joseph McDade, will reverse a 10-year-old Justice Department policy that allows federal prosecutors to speak with represented persons without first talking to their counsel. The bar rules of virtually every state prohibit such contact, but the Justice policy has trumped those rules. Under the McDade amendment, state bar ethics rules shall hold sway. And these rules–many of which may differ from state to state–govern not just represented parties but wiretapping, sting operations, and a host of other ethically thorny practices as well.