i went to australia once and used by debit card in a machine, got the money out perfectly okay, but when i went use it the next day it didnt work. when i phoned up my bank they told me they stopped my card because they assumed someone had nicked it.
so they stopped my card with absolutely no warning, simply because i used it abroad.
so i can understand msafi's point.
but on the other hand, i wouldn't want my customers to know that i was stripping out fraud prevention measures. because no matter what the reason behind it, it's just going to make you look bad.