I think it has to do with the new regs. You can only sell to those that are over 18 now and have to card them if they are 27 or under. I think this is what online shops are going to have to do or ask for a copy of your license. I had a feeling something like this was coming.
Either that or have the delivery service card the recipient of the package. It's probably only going to get worse. They are trying to kill this industry.
Then they can ask for your Driver's lic... not YOUR SS!