Some US citizens and greencard holders who live overseas know that they are considered non-compliant under IRS (US tax authority) rules which are being more stringently enforced in 2009, and they are debating coming in from the cold. Others are only becoming aware they may not be fulfilling their US tax obligations, even though they assumed they were. Read more of this three-part series: http://genevalunch.com/2009/09/13/us-taxpayers-abroad-part-1-us-swiss-treaty-details-may-not-come-in-time-to-help-us-citizens-abroad/