There was a documentary about UK hemp farmers on one of the obscure TV channels a few weeks ago - probably BBC1 or something like that! As Dave mentioned the THC content is next to zero but that doesn't stop people trying to smoke it - apparently hemp farmers on the M25 ring road were banned from growing it due to the number of people stopping on the hard shoulder to pick some flowers!!!!
Hemp seed shortage? Would have been a crisis to me a few years ago, and i rate it as one of the best barbel attractors going but haven't used it at all this season and my catch rate has not suffered. It's good stuff, but not essential.