Now, let's look at what went wrong with the Epsilon data breach. The details of exactly how Epsilon was breached are still murky, but it seems concerning that multiple Epsilon customers were compromised from a seemingly single attack.

Anup Ghosh, Founder and Chief Scientist for , commented, "As we learn more about this breach, it could be very possible that a single intrusion was utilized to gain access to the data across all of these brands. Is this indicative of a potentially broader threat from a cloud perspective? Maybe yes, maybe no - only time will tell as we learn more and pull back more layers of both onions."

Tim 'TK' Keanini, CTO of , agrees. "It's hard to say exactly what Epsilon did wrong but from the magnitude of the data that was taken, it would appear that they could have segmented the data such that if there was loss, it would only be partial. It appears that everything was centralized and when the attackers got at the data, they got it all."

Lesson Learned: Make sure that customer data--particularly sensitive customer data such as email databases, or other private data--are securely segregated from one another. As organizations move processing and data storage to third-party cloud providers, it is critical that the sensitive data be maintained in separate silos so a breach of one customer database is not a breach of all customer databases.

There is a bonus lesson for the companies like Chase, Best Buy, and others that do business with Epsilon and had customer data compromised as a result. Keanini cautions organizations to always assume that any data shared with a third-party will be stolen. Starting from the premise that it's only a matter of time until the data is compromised, organizations are in a better position to weigh the pros and cons of engaging with that third-party, and assessing the associated risk.