Why quote from Webster instead of Black? Because the three legal dictionaries I have in my office don't have this in them.
Anyway over at Volokh and Balkinization there is a discussion of the doctrine behind this. The background is pretty simple. The government is holding someone without charging him with anything. The person files a habeas. The government has purposefully held the individual in possibly the only jurisdiction which would rule in its favor. The courts in that jurisdiction do rule in the government's favor. The person appeals to the Supreme Court where the outcome is far from certain. At this point the government files charges against the person in order to moot the case before the Supreme Court and keep favorable precedent in place.
The argument is that in the case of one party purposefully abusing the system, unilaterally, and causing a case to become moot the underlying precedent can also be made moot.
I'm not an expert in this, and I haven't been following the case, but here are the issues which stick out in my mind:
1) Mootness - As we all know, mootness is not an absolute. If it were there would be absolutely no precedent regarding abortion because no one gets from a trial court, through the appellate courts and to the Supreme Court in 9 months. Now, I don't know what nook or cranny a case wherein one party purposefully set out to void the Court's jurisdiction could fit into but I suspect that a Court not particularly thrilled with being manipulated might bite on it. And, if it did the whole trick might backfire on the government because at this point there is no pressure on the Court to find in the government's favor. If he's charged then what difference does it make if a habeas is granted setting precedent against holding someone without a charge?
2) Applying Vacatur -
The parties in the present case agree that vacatur must be decreed for those judgments whose review is, in the words of Munsingwear, "'prevented through happenstance'"--that is to say, where a controversy presented for review has "become moot due to circumstances unattributable to any of the parties." Karcher v. May,484 U.S. 72, 82, 83, 98 L. Ed. 2d 327, 108 S. Ct. 388 (1987). They also agree that vacatur must be granted where mootness results from the unilateral action of the party who prevailed in the lower court.The appeal above was argued specifically as to Vacatur caused by settlement and denied. However, the dicta above would seem to strongly favor use of vacatur in a case such as this if, and this is a huge IF, you could get the court to accept cert. solely and specifically vacatur. Maybe the Court will be upset enough with the manipulation to grant cert. but I'm not holding my breath.
U. S. BANCORP MORTGAGE COMPANY v. BONNER MALL PARTNERSHIP, No. 93-714
(I'd like to take credit for having found this but it's in the arguments on both blawgs).
As well, does it really accomplish anything? The next guy who's being held in the government friendly jurisdiction is going to get the same treatment. When his case reaches the Circuit Court it may not say it's following precedent but you can pretty much figure they're going to pull out the other decision from an old computer file and just change the names.
If this were a less prominent case so that all the judges in the Circuit didn't already know the result vacatur might make more sense. Perhaps, if there are no more people being held without benefit of the courts for 50 years or so everybody will forget the current case. However, the case is too prominent and I fear this is an issue we will revisit sooner rather than later.