In other words there is no loophole. If they are dealers, you have to do the normal check. If they are individuals, you don’t just the same as buying one from your neighbor. If you purchase a gun off the internet, it must be shipped to an FFL dealer, and you of course fill out the same forms and are subject to the same instant check. I get tired of the idiots talking about a gun show loophole, and that you can just order guns off the internet “no questions asked”. It’s utter BS. I’ve done all the above, on both sides of the counter, too.
Unless you and the seller are close to each other, in which case you can do a face-to-face private transaction. It's not the internet, it's shipping the firearm via common carrier that triggers the requirement that it go to an FFL.