President Obama has said "there is a reason" why Blackberries and smart phones are not allowed in the White House situation room, during a conference addressing reforms to the National Security Agency's intelligence gathering.
Mr Obama noted that many of the countries who have loudly protested against American surveillance programmes themselves seek intelligence on the US.
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Popular channels including Dave and Gold disappeared from sets after a business dispute went unresolved.
Police said it was not clear whether anyone was still inside the store.