Two days after WW published a story exposing rifts between law enforcement and some medical-marijuana operations, U.S. Attorney Dwight Holton and many Oregon district attorneys have issued a stern warning to this booming local industry.

"The sale of marijuana for any purpose—including as medicine—violates both federal and Oregon law and will not be tolerated," says the warning from the U.S. Attorney's Office. "People and businesses that conduct sales of marijuana face the risk of prosecution, civil enforcement action and seizure of assets."

Holton's letter (PDF) was co-signed by 34 district attorneys, the head of the Oregon State Sheriffs' Association and the head of the Oregon Chiefs of Police. One notable absence from the list of co-signers is Multnomah County District Attorney Mike Schrunk. He tells WW his office has different priorities.

"I don't like to threaten things that we realistically are not geared up to do," Schrunk says. "We've been at the forefront of trying to do rehabilitation for drug offenders. We have one of the oldest drug courts in the country. I think we've tried to have a progressive, realistic view."

The first-of-its-kind warning in Oregon is attached to a notice aimed at the "owners, operators and landlords of Oregon marijuana dispensaries." Oregon voters defeated a measure last year that would have established rules for a dispensary system. Nevertheless, dozens of dispensary-style businesses have opened statewide. The growing industry was featured in a WW cover story this year.

Holton's letter follows similar notices this spring from U.S. attorneys in Washington, Arizona, Vermont, Colorado, Montana and Rhode Island. Those letters caused considerable confusion after the Justice Department signaled in 2009 it would back off raiding medical-marijuana operations. On Thursday, U.S. Attorney General Eric Holder announced he would clarify the Justice Department's stance on medical marijuana.