Bitcoin ATMs are becoming increasingly popular in Australia, making the country the fastest growing market for kiosks. Questions are being raised about the source of demand for the controversial service.

Users of such ATMs can insert cash to receive crypto into digital wallets or obtain physical notes from token sales. The U.S. accounts for the vast majority of the market with about 32,000 machines, followed by Canada’s roughly 3,000, according to data compiled by Coin ATM Radar.