A new bill being proposed in Sacramento, CA restricts the sale\trade\barter\free giveaway of live animals (not just fish & coral, but dogs, birds, etc!) on the roadside, swap meet, public areas, flea market, parking lot, outdoor sale, and a few other specific areas. While this bill probably isn't aimed at aquarists, you can see how it would directly affect reef clubs, frag swaps, etc. Tennessee is also considering a version of the bill for their state. You can read and download the full bill here.
http://www.fishlinkcentral.com