Attorney General Jeff Sessions rescinded the Cole Memo, which provided protections for states with legalized cannabis, on Thursday.

The move comes only three days after the most populous state in the country, California, debuted social cannabis sales. The state is expected to launch the world’s largest legal cannabis market.

Sessions’ new policy will now let federal prosecutors in cannabis-legal states decide how aggressively to enforce the Controlled Substances Act, which classifies cannabis as federally illegal. His statement to the nation’s prosecutors is as follows:

“In deciding which marijuana activities to prosecute under these laws with the Department’s finite resources, prosecutors should follow the well-established principles that govern all federal prosecutions.” 

The previous Obama-Era guidance prevented federal prosecutors and the Department of Justice from using funds to go after cannabis-legal states. It is unclear what may result from the new guidance, as prosecutors will most likely be acting on an individual, case-by-case basis as to what funds should be used to prosecute whom and how.