The disclosure of hackers compromising 500 million Yahoo user accounts in 2014 was surprising not only in scope, but also because it became public only months after Verizon had agreed to purchase the technology company this July.

For Verizon, it may have been a rude awakening. But for many mergers and acquisitions practitioners, it was yet another example of a company ignoring modern M&A best practices. For while the breach at Yahoo may have caught its buyers off guard, the modern M&A industry is far from asleep at the wheel as far as cybersecurity is concerned.