Oregon’s top federal prosecutor said Friday the state has a “formidable” problem with marijuana overproduction that winds up on the black market and that he wants to work with state and local leaders and the pot industry to do something about it. U.S. Attorney Billy Williams convened the unprecedented summit of influential federal law enforcement representatives, state officials and marijuana industry scions after Attorney General Jeff Sessions withdrew an Obama administration memo that had guided states with legalized weed on how to avoid federal scrutiny.