Josh Feit at Publicola (bolds are mine):

[E]arlier this month, in order to fight an illegal market that the city (and the legal pot shop owners) say is cutting into the legit market, the Seattle Police Department conducted an evening of buy busts, operating a sting operation out of a motel room on N. Northgate Way. On April 5, eight “runners”—seven men and one woman (all white)—were arrested after undercover SPD officers called a series of delivery services, such as Mr. Green Jeans and Lady Bud, that advertise openly, and bought anywhere from $100 to $260 worth of pot when the delivery person showed up. The police reports note that the arrests were made without incident. The cases have been handed over to the King County prosecutor. (One delivery person was also carrying nine Oxycontin pills, one report notes.)

As Feit notes, the sting means that despite all the progress Washington has made on cannabis, "the SPD is back in the business of arresting people for pot."

Sensitive to the stigma of the failed and racist “war on drugs,” the city says the intent is not to bust people for smoking pot, but to send a message to the owners, operators, and suppliers of the delivery services that delivery will not be tolerated as the city tries to foster the legal pot shop market.

I've written before about why the mayor wants to crack down on delivery services, which remain illegal across the state. Lawmakers in Olympia have repeatedly tried and failed to create a system for legal, regulated delivery. The Stranger stopped running ads for delivery services earlier this year.