John Stossel's premise is complete hog wash. Why does it matter to us that London has half a million cameras spying on British subjects. Is Stossel aware that we fought a war for independence from the tyranny of the English King. The USA is not Great Britain, or Europe, if anything the U.S. should be the opposite of Europe. The country was founded with the idea that government should be small and tightly controlled by the people it serves. We Americans have a long and cherished tradition of not trusting our government and resisting its expansion and intrusion. It does not matter what Great Britain does or how much British subjects like it, we don't want our government spying on our movements or our communications and transactions, therefore OUR government has no business doing it.
As for his claim that surveillance, be it government run or private security cameras was responsible for identifying the Marathon murderers; more hog wash. The government knew about speed bump and his brother PRIOR to their murderous rampage and they didn't need to spy on citizens to obtain their information. The Russians warned them, not once but twice unfortunately they ignored the warnings, people died and no one is held responsible for yet another failure.