Make that a few mainframes for Yahoo! At least 500 million accounts were breached. In terms of number of accounts, Yahoo! has likely set a record for the biggest data breach of all time. (So far.)

If that’s not bad enough, it gets worse: Yahoo! reportedly did not tell its suitor, Verizon, about the data breach until at least two months after Yahoo!’s management found out — and only two days ago. In July Verizon agreed to acquire Yahoo! for $4.83 billion. Verizon might be able to pull out of the deal if it wishes.

Mainframes are widely recognized in the IT industry as the most securable platform. My “(Blank) Needs a Mainframe” series of periodic posts is a reminder that the IT community continues to fail at security, and that mainframes should form part of a holistic answer to fix this massive, growing, industry-wide failure.

This series of posts also¬†reminds the mainframe community to be more vigilant than ever, not to assume that your mainframe environment is invulnerable. I recommend “healthy paranoia.” Every IBM mainframe ships with incredible security capabilities, many enabled by default, and more are optionally available. However, IT teams must know what they’re doing, must stay abreast of developments and technologies, and must competently operate their systems based on the latest information. And here’s a special reminder to CEOs, CFOs, and Chief Risk Officers: if you’re not caring for and investing in your workforce, you are significantly raising the risk of being the next victim of a security breach. “You get what you pay for,” including IT talent (or lack thereof).

Please be careful out there.