Arguments in favor of the Foreign Account Tax Compliance Act start and end with tax invasion. Those who question the validity of a massive and invasive financial dragnet for the purpose of catching a few tax cheats are accused of either being a tax evader themselves or of condoning evasion. FATCA proponents recognize no legitimate cause for concern with handing government so much personal financial information.

These arguments should sound familiar. They’re the same used to justify our massive surveillance state. But not only is the sacrifice of civil liberties unnecessary for national security, the government has proven to be a dishonest and untrustworthy steward of sensitive information.

Andrew Napolitano describes for Reason how spy agencies illegally coordinate with DOJ to circumvent Fourth Amendment protections:

NSA documents released by Edward Snowden show that the feds seriously deceived Congress and the courts in an effort to spy upon all of us and to use the gathered materials in criminal prosecutions, even though they told federal judges they would not. Among the more nefarious procedures the feds have engaged in is something called “parallel reconstruction.” This procedure seeks to hide the true and original source of information about a criminal defendant when it was obtained unlawfully.

For example, if the NSA, while unconstitutionally listening to the conversations of Americans hoping to hear about plots to harm other Americans (it has revealed no such plots from among the trillions of private conversations it has monitored since 2005), comes across evidence of a bank robbery, the NSA will pass that evidence on to the Department of Justice (DOJ). The NSA routinely does this notwithstanding representations to the FISA court that authorizes its spying that it is not in the business of gathering evidence in criminal cases.

…While parallel reconstruction is deceptive, unlawful and unconstitutional, I suspect it is but the tip of a dangerous iceberg spawned by the unbridled NSA spying that Bush and Obama have given us. When you mix a lack of fidelity to the plain meaning of the Constitution with a legal fiction, and then add in a drumbeat of fear, enforced secrecy, and billions of unaccounted-for taxpayer dollars, you get a dangerous stew of unintended tyrannical consequences.

Consider this a warning shot for those who think financial privacy is passé, and that the IRS can be trusted with the massive treasure trove of information that will be coming through the FATCA pipeline. It’s simply naive to believe private taxpayer information won’t ever be passed along to other agencies, or used as a bludgeon to punish political enemies.