The nonprofit, Safehouse, would provide a space for people to use illegal substances under medical supervision, ideally decreasing the number of overdose deaths and diseases spread through shared needles.

While the Trump administration acknowledges the severity of the ongoing opioid epidemic, it does not support such sites, which have been used for decades in Europe with overall positive results.

“One obvious problem with injection sites is that they are illegal. It is a federal felony to maintain any location for the purpose of facilitating illicit drug use,” Deputy Attorney General Rod Rosenstein wrote in a New York Times op-ed last year, claiming that the sites “would only make the opioid crisis worse.”

Despite the controversy, cities including San Francisco, New York City, Denver, and Seattle have all taken steps towards creating such sites. Philadelphia, however, is the one feeling the brunt of the federal government: federal prosecutors filed a complaint against Safehouse on Wednesday.

William McSwain, the U.S. Attorney for the Eastern District of Pennsylvania, told Philadelphia’s local radio station WHYY that Safehouse’s plans—which are supported by the local officials—amounts to “in-your-face illegal activity using some of the most deadly, dangerous drugs that are on the streets.”

“We’re not bringing a criminal case right now. We’re not arresting anybody. We’re not asking to forfeit property. We’re not looking to be heavy-handed,” said McSwain. “This can serve everyone’s interest in order to find out what the court thinks of this. But this, in our view, is illegal.”

Ronda Goldfein, vice president and lawyer for Safehouse, told WHYY that the privately-funded site would be a medical facility with the goal of saving lives and providing avenues to treatment for those who desire it. Thus, she said, it is not illegal under federal drug laws.

“We have a disagreement on the analysis and intention of the law,” Goldfein told WHYY. “We don’t think it was intended to prevent activities such as this, and perhaps it will take a court’s ruling to move the issue forward.”