Our basic policy is: If we make a data mistake (our fault) then we change the rankings. If a school makes a data mistake, then we don't change the rankings, but we generally change the underlying data on the ranking table--assuming the school error is communicated to me.
I wouldn't call that grossly unfair. Academic research would perhaps demand more attention to setting the record straight, granted. But USN&WR's rankings hardly constitute academic research.
[Crossposted to Agoraphilia.]