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Mike Momany smokes marijuana, Thursday, Dec. 6, 2012, just after midnight at the Space Needle in Seattle. Possession of marijuana became legal in Washington state at midnight, and several hundred people gathered at the Space Needle to smoke and celebrate the occasion, even though the new law does prohibit public use of marijuana. (AP Photo/Ted S. Warren)

The marijuana debate

Pot smokers formally gained the right to light up in Colorado on Dec. 10 as Governor John Hickenlooper

signed into effect a controversial ballot measure legalizing marijuana

for adult recreational use in what proponents hailed as a "historic

day."