There are no easy answers to preventing last week’s disruptive hacker attacks on some of the more popular e-commerce sites, a high-ranking National Security Council technology guru warns.

Richard Clarke, the National Coordinator For Security Infrastructure Protection And Counter-Terrorism, assures the federal government will do its part to improve computer security. But, he added, to measurably lessen U.S. businesses’ vulnerability to more intrusions by hackers, market forces also need to drive industry to take ongoing and admittedly costly security measures.