From Redditor /u/fake_fakington:
I gathered all of the IP's in a text file and began enumerating. Some were routers with banner messages I could telnet to - almost all at universities ("Warning! This is a secure system at University of Bla Bla...."). The default Cisco credentials from back in the day worked on most of them, but I didn't poke around. A few of the IPs were web servers with little to nothing on them, mostly Apache on Linux or some BSD, at least one IIS server I can recall.
I finally came upon a web server with a huge directory of HTML files and TIFF images, with a few smaller sub directories containing the same. nslookup returned no reverse records for the IP. A VisualRoute traced it as far as Colorado. The HTML files appeared to be records a psychologist or similar mental health professional would keep. The images were of faxes, apparently of both military and medical nature.
As I browsed from a sub directory back to the parent, at the top of was a new HTML file named something like "1-.HELLO-THERE.html." The time stamp was from right that minute. I opened it, and in plain text was the message "we see you." No quotes, all lower-case. About 15 seconds later the server dropped.