On Wednesday, Colorado sold the first bags of marijuana to legally change hands in the United States since the nation entered a new paradigm of drug enforcement when it and Washington state legalized weed for recreational use in November 2012.

The development has made headlines around the world, but criticism is running high (no pun intended) from some quarters, and restrictions on the law are already emerging.

Two days before New Year’s Day, the Denver Post reported that Denver International Airport would be the first facility in the city to ban possession of marijuana under the new legalization regime, which was by voters’ approval of Amendment 64 over a year ago.

The news was not entirely unexpected, as the "Mile-High City" had already passed ordinances against displaying and transferring marijuana on city property, though possessing pot in city parks, building, schools and other municipal areas is still legal. And an international airport presents a wide range of additional concerns for law enforcement agencies, including the key fact that marijuana cannot cross state lines under the new laws.

"We talked to all of (the federal agencies involved), and they've expressed concern for good reason, but it was our decision based on the way the airport operates," Stacey Stegman, a spokeswoman for the airport told the Post. "We didn't want to impact other airports and other agencies, and we didn't want to facilitate transporting marijuana across state lines."

Stegman added that airport security will not “do checkpoints” or otherwise actively seek out people who defy the new policy, but that if people are found to be in possession of marijuana while being processed for another crime or under other circumstances, they will then be held liable for violating the ban. But people found to possess pot at the airport could be ticketed and face a $999 fine and siezure of their stash, CNN reported.

Any possession or display of marijuana on airport property is prohibited under the policy in order to avoid confusion over the implementation and application of the plan, Stegman added. The new policy will go into effect early this month, USA Today reported.

Some pot smokers in the aptly nicknamed Mile High State were dismayed by the announcement of the rule, but Denver Assistant City Attorney David Broadwell told the Post that individual properties can set their own policies regarding marijuana possession and display.

Rob Corry, a well-known Denver attorney who has been vocal in his support of loose marijuana regulations, agreed that the nation’s fifth-busiest airport is not acting improperly in instituting the ban.

"They are probably within their rights this time, for once," he told the Post. "Not the answer I would prefer, but it is what it is."

Though the airport is owned by the city of Denver, it is also subject to federal regulations, Metropolitan State University of Denver professor and airport security expert Jeffrey Price told the Post.

“Denver [airport] is a commercial service provider, making it a federally regulated facility,” Price said. “So at the end of the day, the airport is usually going to err on the side of the federal government.”