Yahoo! UK Services Limited has been fined £250,000 by the Information Commissioner’s Office (ICO) following a cyber-attack in November 2014.
The cyber-attack left the personal data of approximately 500 million international users at risk.
Because of when the breach happened, the penalty was carried out under the Data Protection Act 1998 rather than the new GDPR, which has a maximum fine of £500,000.
“People expect that organisations will keep their personal data safe from malicious intruders who seek to exploit it,” said ICO Deputy Commissioner of Operations, James Dipple-Johnstone.
“Under the GDPR and the new Data Protection Act 2018, individuals have stronger rights and more control and choice over their personal data.
“If organisations, especially well-resourced, experienced ones, do not properly safeguard their customers’ personal data, they may find customers taking their business elsewhere.”
The ICO focused on the 515,121 UK accounts, that Yahoo! UK Services Limited – based in London – had responsibility for as a data controller.
“The failings our investigation identified are not what we expect from a company that had ample opportunity to implement appropriate measures, and potentially stop UK citizens’ data being compromised,” said Dipple-Johnstone.
The compromised personal data included names, email addresses, telephone numbers, dates of birth, hashed passwords, and encrypted or unencrypted security questions and answers.
The ICO considered the breach to be a serious contravention of Principle 7 of the Data Protection Act 1998, which states that appropriate technical and organisational measures must be taken against unauthorised or unlawful processing of personal data.