A federal appeals court has turned back a $10 million settlement in data breach litigation against Target Corp., concluding the Minnesota judge who approved it failed to consider the interests of customers whose data was at risk in the 2013 cyber intrusion but who had no economic losses.

The ruling from the U.S. Court of Appeals for the Eighth Circuit sets up a debate over one of the thorniest issues in data breach cases—whether and how to compensate individuals for the theft of personal information when it cannot be tied to financial injury.