The IRS is building a vast system to share millions of taxpayers’ data with ICE

The Internal Revenue Service is building a computer program that would give deportation officers unprecedented access to confidential tax data.

ProPublica has obtained a blueprint of the system, which would create an “on demand” process allowing Immigration and Customs Enforcement to obtain the home addresses of people it’s seeking to deport.

Last month, in a previously undisclosed dispute, the acting general counsel at the IRS, Andrew De Mello, refused to turn over the addresses of 7.3 million taxpayers sought by ICE. In an email obtained by ProPublica, De Mello said he had identified multiple legal “deficiencies” in the agency’s request.