Todays revelations of lost customer data by Commonwealth Bank has shown the Turnbull governments weakness yet again in failing to take a stand against big business abuse of consumer data and privacy.

In the wake of the revelations at the banking royal commission, todays reports are yet more reason for Australians to be disappointed in the behaviour of the big four banks.

The failure by Commonwealth Bank to notify customers caught up in this breach is astounding.

The government and the Office of the Australian Information Commissioner must explain, without delay, what they knew about this breach at the time and why no further action was taken.

Its only natural that customers would be worried about the breach - our financial information is one of the most important things to protect.

It took the government three years to implement Labors mandatory data breach notification scheme, which has only just been brought into effect.

Had the government not stalled on that introducing that law, it is likely that Commonwealth Bank would have been required by law to notify affected customers at the time.

As all businesses engage more with information technology, Australians deserve assurance that their data is protected.

We know the government only cares about protecting the banks and giving them a $17 billion tax handout. Instead, they need to stop defending the banks and ensure customers are given the information they need aboutthis breach.