And it's mostly people on phones?pic.twitter.com/AnICeYbgyE
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So I think the answer is that this was linked to from some kind of Google phone app or something and so the referrer is stripped out. Which would make sense. Mystery resolved!
Russian bots?
I mean, but why? Nobody can see the stats but me. (They all are hits from within the US, for whatever that is and isn't worth.)
Failed DDOS?
Nah, they're actually nuking stuff.
BTW, here's another Los Alamosan gone, although not a Manhattan Project person. Well-known in town. http://www.ladailypost.com/content/epifanio-j-trujillo-sr-eppie-oct-27-1923-%E2%80%93-jan-18-2018 …
I may or may not have the nukemap URL as an autofill option that I regularly select
Probably just some botnet poking around. What kind of http requests in the access log?
If your URL isn't HTTPS, then (by default) the Referer is blank for all visits from a HTTPS site.
I used this to demonstrate to my wife what a 100MT bomb would do if it were ever dropped in the city 35 miles to the north of us.
Very clever way to get traffic to your site 
Can you really tell the difference between people that type in the URL and people who start to type a fragment of the website title and the URL is auto-completed by the browser?
Renewed interest in your work probably coincides with the announced re-release of the UK movie Threads, one of the scariest nuclear holocaust movies made.
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