Trash cans and recycling bins are being removed from certain areas of Washington's Metro subway system as a safety precaution.

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Another basic precaution against the small-fry hacker is to turn on security features built into the operating system, Winkler said.

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The system is modeled after military base security protocols in which a color code signifies the level of precaution and perceived threat, according to two officials involved in developing it.

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