Flying by the seat of my pants, this page of information has details which we can guess at - 27,799 are South Korea, 27,690 are Korea Telecom (so close that I'll say it's a 1-to-1 match). Wikipedia tells me as of 2015, KT ran more than 140,000 Wifi hotspots.[1]

Further down the info, we see 28,587 (almost the same number as above) HTTP titles are "Gargoyle Router Management Utility" - which is an opensource variant of the OpenWRT world which patches the code to include the Clacks header.[2]

I'm going to conclude that there's a direct correlation in this data (it all being one and the same endpoint/device pattern) and that 30,000 KT Wifi hotspots across South Korea have their management UI open on the public interface and not locked to the internal network or a VPN, etc. running this Gargoyle patch.

[1] https://en.wikipedia.org/wiki/KT_Corporation

[2] https://github.com/ericpaulbishop/gargoyle/blob/master/patch...