I imagine there's a scholarly article in how warchalking went from the brain of Matt Jones into the public noösphere and then was entirely commodified: Warchalking was supposed to be a way for folks to tag locations with open or closed marks--even a way to advertise that you were offering Wi-Fi as an individual.
The only time I've ever seen a warchalk symbol has been on a business card or a piece of corporate signage. My editorial and advertising partner JiWire built the warchalk symbol into their logo.
Now the ultimate step is Krystal's restaurant, which is adding free Wi-Fi to 243 corporate stores and as many of the 180 franchisees who will pony up for it. Their symbol?
:-)()
!!!
I've got an old box of chalk around here somewhere that I used to tag Dave Sifry's (then CTO of Sputnik) network after a meeting at his house. On our next conference call he was very excited that someone had war-chalked his network, and I had to admit being the tagger.
The war-chalking symbols are very opaque for icons, much like the hobo-symbols they're based on, and amount to a bit of an inside joke between people who've been paying close attention to the wireless industry. Personally, I prefer them to the millions of variations of the original AirPort ')))' radiation icon, which is probably one of the most frequently copied logos in recent times.