Not a problem

U.S. Alerts Schools About Terror Threat

WASHINGTON (AP)--The Education Department has advised school leaders nationwide to watch for people spying on their buildings or buses to help detect any possibility of terrorism like the deadly school siege in Russia.
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After the terrorist takeover of the Russian school, President Bush asked his top advisers to review their strategies for dealing with hostage situations, Homeland Security Secretary Tom Ridge has said.

Easier done than said - remove the metal detectors.