I take your point, and I don't expect any legal action against Augur until (if?) it grows big, by which time it will have less of an obvious core. But there wil

I take your point, and I don't expect any legal action against Augur until (if?) it grows big, by which time it will have less of an obvious core. But there will still be identifiable promoters, e.g. anyone hosting a website advertising/facilitating Augur. I'd guess that these people would be the ones at risk, rather than the individual bettors. Anyway, I'm watching its development with interest, but I suspect that it won't become a big success.