Opinion of the Court
Petitioner Franchise Tax Board of California (Board), the state agency responsible for assessing personal income tax, suspected that Hyatt’s move was a sham. Thus, in 1993, the Board launched an audit to determine whether Hyatt underpaid his 1991 and 1992 state income taxes by misrepresenting his residency. In the course of the audit, employees of the Board traveled to Nevada to conduct interviews with Hyatt’s estranged family members and shared his personal information with business contacts. In total, the Board sent more than 100 letters and demands for information to third parties. The Board ultimately concluded that Hyatt had not moved to Nevada until April 1992 and owed California more than $10 million in back taxes, interest, and penalties. Hyatt protested the audit before the Board, which upheld the audit after an 11-year administrative proceeding. The appeal of that decision remains pending before the California Office of Tax Appeals.
In 1998, Hyatt sued the Board in Nevada state court for torts he alleged the agency committed during the audit. After the trial court denied in part the Board’s motion for summary judgment, the Board petitioned the Nevada Supreme Court for a writ of mandamus ordering dismissal on the ground that the State of California was immune from suit. The Board argued that, under the Full Faith and Credit Clause, Nevada courts must apply California’s statute immunizing the Board from liability for all injuries caused by its tax collection. See U. S. Const., Art. IV, §1; Cal. Govt. Code Ann. §860.2 (West 1995). The Nevada Supreme Court rejected that argument and held that, under general principles of comity, the Board was entitled to the same immunity that Nevada law afforded Nevada agencies—that is, immunity for negligent but not intentional torts. We granted certiorari and unanimously affirmed, holding that the Full Faith and Credit Clause did not prohibit Nevada from applying its own immunity
