Besides the extraterritoriality issue, the other problem with FATCA is that it makes Americans living overseas (99% of whom are just normal people not trying to evade taxes) radioactive to overseas financial institutions because of the potential consequences of failing to report on someone's accounts properly.
Sadly a lot of Americans hear "foreign bank account" and immediately think "tax evasion" without realizing there are a lot of ordinary Americans overseas who just want to pay the rent and save for retirement but can't because Uncle Sam follows us wherever we go for life.
Sadly a lot of Americans hear "foreign bank account" and immediately think "tax evasion" without realizing there are a lot of ordinary Americans overseas who just want to pay the rent and save for retirement but can't because Uncle Sam follows us wherever we go for life.