As a general rule, courts decide cases or controversies; they do
not render advisory opinions in the absence of a real
dispute. Of course, a defendant cannot automatically moot a
case simply by ending its unlawful conduct once
sued. Otherwise, a defendant could engage in unlawful conduct,
stop when sued to have the case declared moot, and then pick up
where he left off. To address this concern, the
"voluntary cessation doctrine" provides that a defendant
claiming that its voluntary compliance moots a case bears the
burden of showing that the alleged wrongful behavior could not
reasonably be expected to recur.
The Supreme Court recently had occasion to apply the doctrine in
the case of Already, LLC v. Nike, Inc., 133 S.Ct. 721
(Jan. 9, 2013). In that case, Nike sued Already for trademark
infringement for illegally copying its "Air Force 1"
shoes. Already counterclaimed that Nike's mark was invalid
and asked a federal judge to cancel it.
