While more states embrace legalizing medical marijuana, others are still struggling to make sense of their own pot laws, especially when it comes to marijuana and the workplace. That conflict could play out next in Rhode Island, where the state's chapter of the American Civil Liberties Union plans to file a complaint against an employer that the group says has refused to hire medical marijuana patients, despite the drug being a legal treatment in the state for almost a decade.

Neither the employer nor the plaintiff has been named. A news conference scheduled for Monday to discuss the lawsuit was postponed because the plaintiff had a family emergency, the group said. A spokeswoman for the ACLU of Rhode Island said the organization couldn’t comment further at this time but that “as soon as we are back on track, we will have something.”

Such complaints are not uncommon and point to one of the most familiar predicaments many marijuana users find themselves in during the era of legal weed: Just because someone can’t be arrested for it, doesn’t mean there aren’t consequences for smoking pot in privacy. Public opinion, better research into the benefits and harms of marijuana use, and the attitude that supporting marijuana legalization no longer makes a politician an outlier all point toward a future in which pot is consumed and regulated like alcohol. Until then, there is often more uncertainty than clarity when it comes to legal marijuana consumption.

Blurred Lines

In states where patients have access to medical pot, the line between what constitutes a fireable offense and what doesn’t is often blurred. States with lax marijuana laws generally don’t protect marijuana patients in the workplace. Of the 23 states where medical weed is legal, only two -- Arizona and Delaware -- have laws barring employers from firing a marijuana patient for failing a drug test. Even then, things can get tricky. If an employer can prove that an employee’s marijuana use might impair workplace performance, the law allows that employer to take action. No state protects recreational marijuana users from being fired for failing workplace drug tests, even if they’ve never shown up to work high.

Some state laws contain language that may support medical marijuana users’ claims for civil protections, but courts often side with federal law that says any marijuana use is strictly prohibited. In California, which in 1996 became the first state to legalize medical marijuana, state law protects marijuana patients from “criminal prosecution or sanction” -- assuming their marijuana licenses were obtained legally through a physician. But it does not require “any accommodation of any medical use of marijuana on the property or premises of any place of employment or during the hours of employment.” California lawmakers attempted to enact legislation in 2008 that would have protected patients from being fired for failing a drug test, but former Republican Gov. Arnold Schwarzenegger vetoed the bill. In fact, courts in California have often upheld employers’ decisions to terminate medical marijuana patients, often arguing that federal law trumps state law when it comes to marijuana use.

Then there are businesses that receive federal funding or are subject to federal regulations, such as the Department of Transportation. Such employers must adhere to the Drug-Free Workplace Act of 1988, which requires those businesses to take comprehensive steps to keep their workplaces free of drug users.

Previous Cases

The ACLU’s effort in Rhode Island isn’t the first time a company has been sued for allegedly treating medical marijuana patients unfavorably. In 2010, Brandon Coats of Englewood, Colorado, filed a lawsuit against Dish Network, claiming he was wrongfully terminated after he tested positive for marijuana in a company drug test. Coats, who worked as a telephone operator, was a paraplegic who used pot to ease muscle spasms -- a condition that he said would have prevented him from working in the first place. An appellate court sided with the employer in 2013, saying companies in the state could lawfully fire workers for failing drug tests.

Then there was the case of Walmart employee Joseph Casias of Michigan who, in 2009, was fired for testing positive for THC (tetrahydrocannabinol, the psychoactive ingredient in marijuana). Casias used marijuana to alleviate symptoms of his sinus cancer, Fortune reported. A court upheld his firing, despite medical marijuana being legal in Michigan.

Rhode Island legalized medical marijuana in 2006. State law bars employers from refusing to “employ … a person solely for his or her status as a [medical marijuana] cardholder.” At the same time, the law does not compel an employer “to accommodate the medical use of marijuana in any workplace.”