Morrisons workers whose payroll details were leaked by a disgruntled employee will not receive compensation, the Supreme Court has ruled.
The supermarket giant was not liable after an internal auditor leaked payroll data of about 100,000 workers as "revenge", judges decided.
The decision overturns a landmark class action case by 9,000 people in a claim for being left "upset and distressed".
The claimants' lawyer said he was "hugely disappointed".
Morrisons faced the action after internal auditor Andrew Skelton leaked the data after being issued with a verbal warning.
Skeleton, who worked at the firm's Bradford head office, posted workers' personal details on the internet and sent them to newspapers.
However, a panel of five judges unanimously concluded Morrisons was not "vicariously liable" for his actions.
The president of the supreme court, Lord Reed said: "Skelton was not engaged in furthering Morrisons' business when he committed the wrongdoing in question."
However, lawyers for Morrisons argued the firm was "entirely blameless" and would be exposed to "compensation claims on a potentially vast scale" if the decision stood.
Nick McAleenan, a lawyer represented the claimants, said: "The Supreme Court's decision now places my clients, the backbone of Morrisons' business, in the position of having no legal avenue remaining to challenge what happened to them."
In July 2015, Skelton was jailed for eight years after being convicted at Bradford Crown Court of fraud, securing unauthorised access to computer material and disclosing personal data.
In a statement, the supermarket said: "We are pleased that the Supreme Court has agreed that Morrisons should not be held vicariously liable for his actions when he was acting alone, to his own criminal plan, and he's been found guilty of this crime and spent time in jail."