The vandals struck in the middle of the night, hurling Molotov cocktails through the windows of two medical marijuana businesses and spray-painting "NOT IN OUR TOWN" just before the Billings City Council was supposed to take up a ban on any new pot shops.
Montana and other states that have legalized medical marijuana are seeing a backlash, with public anger rising and politicians passing laws to slow the proliferation of pot shops and bring order to what has become a wide-open, Wild West sort of industry.
They are looking to avoid what happened in California, which allowed the pot industry to grow so out of control that at one point Los Angeles had more medical marijuana shops than Starbucks — about 1,000 by one count.
"Yeah, it's out of control — and it needs control, if not extinction," Montana Sen. Jim Shockley said Friday. "There's no control over distribution. There's no control over who's growing it. There's no control in dosage."
Fourteen states have legalized medical marijuana, beginning with California in 1996, and the District of Columbia followed suit this month. The laws allow chronically ill people to buy marijuana with permission from a doctor.
But many of these states passed their laws without working out the details. And they weren't ready for the boom in pot shops that occurred this past year after the Obama administration announced it wouldn't prosecute medical marijuana users.
In some places, law enforcement officials and civic leaders are complaining that there are too many marijuana dispensaries, that buyers and sellers are falling to robberies and break-ins, that driving-under-the-influence arrests are on the rise, and that the pot is being sold indiscriminately and winding up on the black market.
Some state and local governments are now rushing to put regulations in place.
Colorado lawmakers passed sweeping rules this month for pot growers and the estimated 1,100 shops selling marijuana, creating a new state bureaucracy led by auditors and criminal investigators who would monitor the industry to make sure, for example, that the drug is being sold only to patients who have a doctor's recommendation.
Regulators expect only about half of the state's dispensaries to continue operating under the stricter rules.
The Billings City Council approved a six-month moratorium on new medical marijuana businesses in May after the violence against pot businesses the previous two nights. On Thursday, the city of about 90,000 people ordered 25 of Billings' 80 or pot businesses to shut down after discovering they were not properly registered with the state.
"I was hoping this would be a more civil discussion," City Councilman Denis Pitman said after the firebombings. "I wish it wouldn't have gotten to this level."
Los Angeles officials recently ordered the shutdown of hundreds of dispensaries and took steps to ensure that the remaining ones meet stringent new guidelines. Owners must undergo a background check, their stores must be 1,000 feet from schools, parks and other gathering sites, and their pot must be tested at an independent laboratory.
Montana's medical board is considering curbing mass screenings and teleconferences that make it easy for people to get a marijuana card. Montana in recent days has seen "cannabis caravans," mobile operations that pass through town, charging people $100 to $150 for a doctor's recommendation to smoke pot.
The push for tighter regulation has infuriated medical marijuana users.
"They are creating ordinances and moratoriums that are blatantly against the law," said Jason Christ, founder of the Montana Caregivers Network, the group that organizes the cannabis caravans. "They do not serve to protect the welfare of our citizens, and they do no good."
In Colorado earlier this month, veterans in wheelchairs, college students and dispensary owners packed legislative hearings to speak out against the regulations. The hearings lasted eight hours and reached a fever pitch when several people had to removed for shouting at lawmakers.
Medical marijuana has been around for more than five years in Montana, but the boom came this past year. The number of registered users in Montana, a state with a population of just under 1 million, has gone from 2,923 last June to about 15,000 today. The number of registered suppliers has increased from 919 to about 5,000.
The number of DUI arrests involving marijuana has skyrocketed, as have traffic fatalities where marijuana was found in the system of one of the drivers, Montana narcotics chief Mark Long told a legislative committee last month.
Also, Montana confidentiality laws prevent law enforcement from knowing where most medical marijuana businesses are, and civic leaders complain they don't know whether the shops are up to city and fire codes or close to churches, schools or parks.
During Colorado's legislative debate, state Sen. Chris Romer quoted the Grateful Dead as he pondered the spectacle of lawmakers actually passing regulations for the legal sale of marijuana: "What a long, strange trip it's been."
Associated Press writer Colleen Slevin in Denver contributed to this report.
© Copyright 2016 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.