Mystery Referer ("-") Solved! (Possibly.)

Followup to a previous thread about surges of mystery traffic.

[CheeseburgerBrown]

In the thread linked below I asked for any insights anyone might have about getting deluged with a blast of traffic which, despite coming from various IPs, all have the referer field filled with only a hyphen.

[webmasterworld.com...]

I had theorized that this might be due to a 301 Redirect a have in place for an old URI for the resource being deluged -- perhaps redirected traffic wasn't passing along a referer. An unproved hypothesis. Anyone smart wanna chime in?

...The new theory: I decided to paw through my raw logs for the month manually (as opposed to with a log analysis tool), and saw that the lion's share of my unexpected traffic has been coming from various ISPs belonging to the US Army Corps of Engineers.

They seem to like my cartoons.

So, it may or may not be a complete answer, but it kinda looks like the Corps of Engineers authorized web-access computer configuration uses software to hide the referer, across the board. I have hits from dozens of bases and (what I think are) several ships, all with stripped referers.

Anyone here in the US Army? Care to comment? Can you confirm or deny this theory?

[leadegroot]

They are probably passing the link by email, which would not supply a referrer.
I had that happen once - I had a page displaying some sort of clock thing and it passed virally around the world - I was watching the IP addresses passing through different countries with fascination as the 'meme' passed from group to group. No referrers, all referrals by email.