I think the reason Oregon is picking on homebrew is due to a severe tax deficit. They had attempted to pass some controversial legislation (not sure if it passed) that increased the taxation on beer sold in the state by something ludicrous, like 200% or 2,000%. As you may know they're home to a lot of craft breweries, so it was a mystery why they were taking such a neo-prohibitionist approach to get money in the coffers while hurting the state economy. In any case, I'd bet money that any legislation that limits the production, or transport, of homebrew would be related to this. Probably to encourage people to buy commercially-produced beers and pay the asinine tax imposed on them.