For those who do color outside the lines, the repercussions can be harsh.
In Montana, a 2004 voter-approved medical pot law was vague on local law-enforcement's abilities to regulate commercial activity. The feds stepped in when the number of registered pot providers topped 4,800 with billboard ads and huge greenhouses operating in the open.
Raids in 2011 led to the convictions of 33 providers and, coupled with a major rewrite of the state law, led to the demise of most commercial sales.
U.S. Attorney Mike Cotter, who orchestrated the crackdown and vows to prosecute large pot providers, said the new DOJ memo is "not going to affect the way we do business here in Montana."