The State could be liable to pay compensation to the three million people who have Public Services Cards, according to a legal expert.
An Oireachtas Committee has heard the Government may be in breach of new EU data protection laws, if it continues to expand terms of the PSC.
Later this year people will need a Public Services Card to get a drivers licence or passport, as well as social welfare payments.
Solicitor Simon McGarr from Data Compliance Europe says the state could be liable for a big payout.
"If it is the case that the Public Services Card's database, the single customer view database, is not compliant - and I've set out why I think it's not compliant, it can't be compliant under the current system.
"We told that it's currently containing approximately three million individuals details: that would indicate that each one of those three million people have a claim on the State."