Yet another important finding of the “2009 Annual Study: Cost of a Data Breach” by the Ponemon Institute, sponsored by PGP, concerns the acute damage caused by lost or stolen laptops and other mobile data-bearing devices, as compared with other breach vectors.

On page 23 of the report, we find the highlighted finding:

Thirty-six percent of all cases in this year’s study involved lost or stolen laptop computers or other mobile data-bearing devices. Data breaches concerning lost, missing or stolen laptop computers are more expensive than other incidents. Specifically, in this year’s study the per victim cost for a data breach involving a lost or stolen laptop was just under $225, over $30 more than if a laptop or mobile device was not involved.

This goes to reinforce, then, that when it rains, it really pours, where laptops and mobiles are concerned. They tend to be an all-or-nothing vector, thinking of the quantities (and often qualities) of breached data involved, and when it’s “all,” it’s an expensive incident.

Most people focus first on their most significant risks, and laptops and other mobiles certainly rank highly, both by their sheer ubiquity and also by this figure highlighted in the Ponemon study. Close the biggest holes first if you can.

And don’t forget to read the whole report if you can.