So people would create a routine circuit where they have dollars, buy bitcoin on US exchange. Send bitcoin to foreign exchange, sell bitcoin for that national currency (sometimes dollars). If possible, that exchange would allow wiring out, back to the user's real bank account. In other cases that exchange would have a bitcoin or national currency market of another cryptocurrency, like litecoin, where an arbitrage opportunity MIGHT still persist.

The litecoin would be moved and liquidated back on a US exchange.

Got to calculate it yourself and figure out why the arbitrage opportunity is still there. Usually there's a good reason. Sometimes there's a good reason that you are exempt from, and in those moments you borrow as much as a can get your hands on and make 5% profits as much as possible.