Think about it though. Would they really need to guard the ice wall?
How many people want to go to Antarctica? also, I think (a while back) we were talking about the possibility of the Earth's magnetic field fumbling with the explorer's equipment, making it seem that you were walking south, when in fact you were not.
Okay, so even if someone makes it to the ice wall, it would be difficult at best to return. So, when you get home, nobody believes you.
There's really nothing you can do about it either. I don't think we'd need to guard the ice wall, just keep enough 'legitimate' science pushed down every kid's throat so that they forget that they ever wanted to go to the South Pole.