It's best just to renounce your US citizenship if living abroad. You can always get it back if you move back.FATCA is designed to identify suspected U.S. persons at financial institutions outside U.S. rather than to enforce collection from foreigners. FATCA requires foreign financial institutions to report information related to the overseas assets suspected to be held by U.S. persons.[4] Under U.S. tax law, U.S. persons are generally required to report and pay taxes on income from all sources.[5] Taxpayer identification numbers and source withholding are used to enforce foreign tax compliance. For example, mandatory withholding is often required when a U.S. payor cannot confirm the U.S. status of a foreign payee.[6] The United States levies income taxes on its citizens, regardless of residency, and therefore requires U.S. citizens living abroad to pay U.S. taxes on foreign income (minus credit for foreign tax paid).[7][8][9] For this reason, the increased reporting requirements of FATCA have had extensive implications for U.S. citizens living abroad.
http://en.wikipedia.org/wiki/Foreign_Ac ... liance_Act
If not, fill out the US tax form each year to avoid trouble.