[Read: Good News, Bad News for Tax Refunds.]
"You could get the tax gap down close to zero, but it would certainly not be a good policy to spend that much," says Michigan policy expert Slemrod. "Nor is it advisable in the same way that it is not good policy to put someone on every corner of every street to eradicate street crime."
Technology and law experts say that for such major expansions of government into people's lives, simply doing what is legal could have unintended effects that could be detrimental to a system that requires cooperation from taxpayers and the legal community.
"When technological change in the ability to analyze and aggregate data allows activities that are different, not just in degree, but in kind, we as a society should have the ability to think about whether or not we should go down that path," says Surden, who worked as a programmer for Cisco Systems before studying law at Stanford University. "As a publicly accountable agency," he says, "the IRS should make the public aware if technology is allowing them to analyze data in ways that were not possible in the past. That should be an open discussion we all participate in."