On April 23 Lindsey and Josh Rinehart were driving back to Boise, Idaho, after a hiking trip when they got a frantic phone call: Police were searching their house. By the time the Rineharts made it home, their babysitter was a mess, and their two children—along with the children of a friend who'd gone hiking with them—were gone.

Here's what happened: As the Rineharts and their friend Sarah Caldwell were returning from their trip, Boise police were following up on a tip from a school administrator who reported that an 11-year-old student, not related to either Caldwell or the Rineharts, had gotten sick from eating marijuana. According to a statement released by the Boise Police Department, "witnesses" told them the marijuana came from the home of the Rineharts, who both happen to be prominent medical marijuana activists.

Police went immediately to their house, where they demanded that the babysitter let them in. After checking on the kids (Caldwell's two sons and the Rineharts' two sons, all of them fine), police commenced snooping through the house without a warrant. They struck gold in Lindsey and Josh's bedroom and freezer, where they found "drug paraphernalia, items commonly used to smoke marijuana, and a quantity of a substance that appeared to be marijuana in locations inside the house accessible to the children."

Lindsey Rinehart used that marijuana to treat her multiple sclerosis, but Boise police nevertheless contacted Idaho Health and Welfare officials, who put all four children "in the protective custody of the state until it can be determined they are in a safe environment."

While the Caldwell boys were returned to their mother a few days later, the Rineharts had to wait a full week before the court granted them a single supervised visit with sons Elijah, 5, and Laustin, 10.

After nearly two weeks without her children, Lindsey Rinehart posted on Facebook, "This feels like the worst nightmare that I have ever had and no matter what I do I can't wake up."

She's not alone.

While there's no national count on how many parents lose custody of their kids each year due to marijuana, Keith Stroup, founder of the National Organization for the Reform of Marijuana Laws (NORML) told The Daily Chronic earlier this month that his team gets calls "three or four times a week from people who have lost custody of their children because they tested positive at birth or in a situation where parents are feuding over custody." In 2011, The New York Times reported that "hundreds of New Yorkers who have been caught with small amounts of marijuana, or who have simply admitted to using it, have become ensnared in civil child neglect cases in recent years." In 2010, Americans for Safe Access told CBS that it had received 61 calls since 2006 from medical marijuana users who had their visitation rights threatened.

Activists say those numbers on the rise. "It's something we're hearing about more often now than we used to," says Amanda Reiman, California policy manager for the Drug Policy Alliance, largely because policy hasn't kept up with cultural changes—even in states that have adopted medical marijuana laws.

"If [illicit] drugs are found in the home there has to be immediate action," says Reiman. "This is based on the false presumption that the presence of marijuana poses a danger. We know that there are things in the home—prescription drugs, cleaning supplies, knives—that are not necessarily indicative of child endangerment. And if someone is a licensed gun owner and has a gun at home, that's not necessarily a danger to kids." Social workers simply aren't allowed to extend that discretion to marijuana.

And the story is seldom all that different in states that allow medical marijuana. Why? Because no piece of medical marijuana legislation includes protections for parents.

"You have a medical marijuana law, but how that affects different areas of the same code isn't clear," says Chris Lindsey, a Montana-based medical marijuana attorney and legislative analyst for the Marijuana Policy Project. (Also: a father of one.)

"For instance," Lindsey adds, "the law says you can consume marijuana if a physician says you can. But what if that patient is pregnant? What is the hospital supposed to do if they think a child is at risk? You don't have the guidance of the law when making these decisions. If they don't like the person, if they don't believe that marijuana is medicine, that's how they make their decision."

Reiman concurs. "Even though medical marijuana patients don't have any formal protections, being in a state where you can obtain a recommendation for medical marijuana is definitely helpful." In states without medical marijuana laws (like Idaho), Reiman says that custody decisions are "really going to come down to how the judge feels about marijuana. And that's unfortunate."

Even though the deck is stacked against them, there are steps pot-using parents and their attorneys can take to preserve parental rights.

"One rule is that you need to make sure that you are not impaired as a parent," Lindsey says. "That's no different than alcohol. The department of family services in any state does not want parents that are so drunk that they can't take care of their children. That does not mean parents can't have a glass of wine."

Another rule: Keep pot where kids can't easily get to it. "Parents aren't expected to have a gun safe for their medicine. But a marijuana cookie shouldn't be kept on the bottom shelf. There's a line there."

When all else fails—and it often does for poor parents and parents of color—it's important to frame these incidents in a way people who don't use marijuana can understand. Not too long ago Lindsey had a case similar to the Rineharts'. A teenage girl was staying with a sitter while her parents were out of town. One day she snuck back to her house without her sitter's knowledge, and stole a few of her parents' marijuana edibles, which she then took to school. All hell broke loose when she got caught, and her parents came under fire.

"When children do things that they know they're not supposed to do, to what extent are parents culpable for that? You can't chain your kids to the bedpost at night," Lindsey says. "In that case I argued that we've got a young child who raided the liquor cabinet."

It's been more than two weeks since Laustin and Elijah Rinehart were taken from their parents. Thanks to an understanding social worker, the Rineharts now get to have the boys after school until 6 p.m., when they are returned to their foster home. Unless the district attorney decides to press felony charges against Lindsey and Josh, they're likely to get their kids back.

"Not treating with cannabis does suck though," she wrote on Facebook. "Pain levels are rising, muscle spasms, 'sagging' around right side of my mouth is starting, same with my right eye."

It's a compromise she's willing to make, but shouldn't have to, says Reiman. "What has happened to those kids as a result of being taken from their home and put in foster care? That needs to be measured against the impact of living with a parent who uses medical marijuana."