While marijuana use was legalized in New York last March, sales of the drug were barred until the state could develop regulations and issue licenses. But many businesses, unwilling to wait, began selling cannabis anyway, in some cases as “gifts” to customers making another purchase.

Now, state authorities are cracking down.

The state Office of Cannabis Management said Tuesday it sent cease-and-desist letters to more than two dozen businesses, demanding they halt sales immediately. Violators will be subject to “substantial fines and possible criminal penalties,” the letters said, and could lose the right to win a legal license.

“We want to make sure these operators fully understand the law and the consequences they face,” OCM executive director Chris Alexander said in a statement, “and now that these letters have been sent, we fully expect them to cease and desist their activities – if they don’t, we will take action.”

NY1 reported last month on one business, Empire Cannabis Clubs, that advertises itself as the city’s first cannabis dispensary. The business operates as a not-for-profit membership club, providing cannabis only to those purchasing a daily or monthly membership.

The process of standing up a regulatory framework for the industry is expected to take up to a year or longer.