27C3, CCC Camp 2011, and 28C3 all had their own GSM networks as well. http://events.ccc.de/congress/2011/wiki/GSM#GSM_Network_at_2... It was really interesting talking to the crew running it and discovering how GSM works. Hopefully they'll be back this year at 29C3

Wow, I saw 27C3's little experiment but I didn't realize 28C3 had a network connected to the public phone infrastructure.

Yep. For those like myself who didn't have a german SIM for the week it was very useful.

Also HAR and I believe Burning Man had GSM networks too.

Burning Man's GSM network used the GNU Radio project:

http://gnuradio.org/redmine/projects/gnuradio/wiki

The Suggested Reading section gives a really good starting point to DSP, electronics (including Radio and RF design), and Programming (C++ and Python). It's been a great help to hobbyists like me.

H.O.P.E. had its own GSM network, too. All it took to use was getting one of the customer SIM cards.

The only thing I could think of when I read that article is; how long until Coca-Cola sends a C&D against them for likeness of Ninja-Cola? Very interesting otherwise.

Unless their logo is like cokes, there are plenty of beverages that are called such and such cola. I might be wrong, but I don't think just cola is a big deal to them.