Everybody moves at the same time. No ripple, just a quick and simultaneous changing of location.
And yes, practical physical limitations have to be ignored. That's why it is a thought experiment and not a fantastic way to make an infinite amount of profit in just one day.
The best part of course, would be that even though the taxman would take an infinite amount of money, you'd still have an infintite amount left (unless the tax rate happens to be 100%).