Gun shows are for newbies looking for felonies. Plenty of dealers always selling clear as day post ban mags to whoever wants to buy them. Not that you shouldn’t be allowed to buy them, it’s just that some of these dealers are selling to people who are truly clueless to the risk they are taking.
meh. At the price the vendors get for those mags (rape) not many newbies are going to be buying them, so it's a self limiting prophecy.
Not to mention there's about a thousand other things that are worse for a newbie to do than buy a postban mag.