you could observe the same thing when the ccc guys had their first gsm phones. Someone just showed up with a base station in the trunk of his car. compare that with the huge buzz that went around the same thing at defcon a couple of years ago. The defcon truck definitely looked WAY cooler.
but on topic what's actually really scary about this is that even newer smartphones would allow sim exploits to roam free. contrary to what you may think it's not just old phones.
[1] http://events.ccc.de/camp/2011/Fahrplan/events/4427.en.html
EDIT: while technically not exactly the same as opensimkit here's an answer to the why question posed by jacob appelbaum. I suspect the same applies here(and it's not really a bad reason either)
https://mailman.stanford.edu/pipermail/liberationtech/2013-J...
The iPhone has a menu option within Settings > Phone > Sim Applications where these are displayed. I haven't seen this on other SIM cards
USSD codes are critical.
I travel a lot and use a hacked up Chinese phone since it supports dual SIM pretty well but I'd rather use an iPhone. Unfortunately I want both my US and UK numbers and contacts slightly more.
unless sims in brazil were that outdated/insecure at the time
I played around with a TurboSim for a while too back when I was testing out a SIM card 'firewall' that would block the carrier programmed SIM from responding to OTA updates or type-0 stealth SMS and other bad things http://www.bladox.com/ then phones with wifi that didn't require a SIM came out.
https://www.facebook.com/notes/airtel_in/airtel-launches-the...
And that was a few years ago.
Edit: Found a PDF from 2006 that talks about even higher spec SIM cards: http://www.spansion.com/products/documents/hd_sim_whitepaper...
Havent had a chance to watch the presentation, perhaps its already answered there: Are these totally locked down or is it within realms of possibility to take out the SIM card from an average GSM phone and start poking around, adding one's own applications.