Yes, but it becomes a little bit like pushing mercury. Outside of the G-20, even if you implemented a FATCA for the G-20, there might be a 21st, a 23rd country that would not comply with FATCA. There are probably financial institutions that are not complying with FATCA because they may not want to carry on business in the U.S.
Canadian banks do carry on business in the U.S. and the penalty for not complying with FATCA is severe.