It said that insurers would pick up the bill for business interruption losses, which are not covered by the scheme.

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Adam Rose, an economist at the University of Southern California, prefers to include only direct costs such as business interruption and property damage.

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Should the shareholders of those companies bear the consequences of a business interruption, lost data, or whatever else occurs as a result of such a counter attack?

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Smart insurers are increasingly aware of the way in which life, property, business interruption and other risks interact a portfolio risk-management approach encouraged by both regulators and investors.

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There's "contingent business interruption" insurance for that.

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Officials should be aware that in the past several years insurance companies have begun to market specific computer policies that may provide first and third-party coverage for losses associated with cyber incidents, such as costs for data restoration, crisis response, privacy notification and forensic investigation, as well as defense and indemnification arising out of cyber incidents, and business interruption.

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For instance, homeowners' insurance typically does not include flood coverage, which is underwritten by the federal government, and business-interruption insurance may not cover losses from looting.

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The bombs caused some property damage, but Boston and industry officials said the biggest cost to the insurers is expected to come from "business-interruption" claims stemming from the nine-day cordoning off of the bombing scene.

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