... why not
- Install them on their own VLAN in stores - Deny the VLAN internet access
An insider (private "security" or janitor) could yet attach an infection device to the private network (which is a likely infection vector in any case). The only "simple" solution leveraging XP that I can envision is one where each and every POS is physically isolated from the network via a very locked down BSD or Linux machine (Pi's?).
The thing is, dear author... The ability to automate one's work by computer (scripting, coding, etc.) is now truly an absolute essential if one is to compete in any valuable job today. In the work that I do in device testing. Where we used to do a lot of hands-on work in measuring "stuff" on our devices, now we automate that work. There is also a cascading effect... Such automation gives us reams of data that again must now have some automated method of culling it for more in-depth analysis.
If a person is truly computer illiterate, I don't recommend hiring them at my place of business any more. Additionally, there are people from outside our country that are prepped for this work and will take and "do jobs that natives won’t do" (tilting hat -- slightly askew -- to Dubya). The jobs of the future -- especially the valuable ones -- require computer literacy.
The basic problem I see is that the fundamentals of business AND of societal expectations upon business are changing, and we must adapt to that change.
Thing #1 - Yes, we are now on the verge of comoditizing the tools for the production of goods and for the automation of that process as well. Think of 3-D printing, of web frameworks, of robotics, of the commoditization that open source brings us -- these are making and will make a small team capable of doing great things with little investment and quickly.
Thing #2 - Government intrusion into the healthcare system is pushing hard on companies to be ultralean and is also forcing the majority of the workforce that is not part of the core into a 29 hour work week -- both of these are caused by ultra-lean companies need to avoid having to "deal with" the government mandated healthcare system.
So... this will be the new structure... and we have to be ready for it. The requirements for working in an ultra-lean company in the US are going to be much different than working in a traditional company... It is going to require higher education, more technical higher education, and multi-disciplinary people. It is also going to require programmming skills for every single member of the core (non-temp) team.
But, if you think about it a moment... instead of dwelling on the chance of the unrest of an "unprepared" society -- if society prepares itself and embraces the change... this is such an exciting a time in history. Never in the history of the world has there been more opportunity to be successful and for so few to touch so many lives. People are empowered as never before to produce an individual contribution to society. There is more to the world than brick and morter, and more freedom accessible than ever before for those willing to sieze on the opportunities at hand.
Let's teach our generation to cast off the old unproductive model and embrace the new and more fullfilling model of the future.
"All we are given is possibilities -- to make ourselves one thing or another." -- Ortega y Gasset