Telstra chairman John Mullen, who was chairman at Toll Group when it was crippled by ransomware attacks in 2020, says big new fines for failing to protect data won’t keep directors up at night, and warns that it is dangerous to create an overly adversarial relationship between the government and business when breaches occur.

Mr Mullen said rather than worry about fines, company leaders would be more concerned about the damage a successful cyberattack could do to a business’ operations and reputation, and the growing fear of unknown new attack vectors being cooked up by persistent criminals.