Not sure why this is legal.
This should never have been permitted to begin with. Since it was strong-armed against defendants as part of a plea “agreement,” the Courts were bound to either accept the agreement in toto or reject it and set the case for trial. Considering all plea agreements to some extent come with an element of coercion, the Courts could not say the deal was “involuntary” and followed along.
I applaud Attorney General Sessions for this long overdue policy decision, but this policy will only last as long as the current administration. What is needed here is a clear Congressional statutory prohibition of this extortionist tactic, so that it will take a repeal of a Congressional act to ever allow it again.