Sen. Ted Cruz (R-TX) is ripping the Internal Revenue Service after the agency sent him a one-page, pro forma response to a series of questions prompted by its audit of Breitbart News Network.

In the Sept. 25 letter, IRS Commissioner John Koskinen said the IRS could not answer some of Cruz’s questions – including how many other news organizations had been audited under President Obama and whether the agency had communicated with White House officials about auditing Breitbart – because of taxpayer confidentiality rules.

“As you may be aware, section 6103 of the Internal Revenue Code limits our ability to disclose confidential taxpayer information, including information bout whether a taxpayer has been audited, absent express authorization from the taxpayer,” Koskinen wrote.

Koskinen, who has been grilled by Congress in recent months over the agency’s targeting of conservative groups that were seeking nonprofit status, went on to say that in the “radio and television broadcasting, subscription programming, news syndication, and information services field,” the IRS has conducted 1200 audits since 2011.

Questions from Cruz unanswered by the letter included “How many other news organizations have been audited since President Obama has been in office,” “At what point does the IRS decide to take action to audit a news outlet,” and “Did the IRS ever receive any communications from any elected official asking it to examine Breitbart News Network, LLC?”

In a statement, Cruz unloaded on the response, saying the IRS could have easily responded to his inquiry without implicating confidentiality rules.

“”None of these questions implicates taxpayer confidentiality. All of them are policy questions, well within Congress’s oversight responsibilities. In response, the IRS has simply said, colloquially speaking, ‘pound sand.’ No executive agency should demonstrate such contempt for Congress, much less for the First Amendment,” Cruz said.

“Every media organization, whether liberal or conservative, should be outraged by the targeting of other media organizations for their political views. As Pastor Niemoller observed, if the media remains silent, there may be no one left to speak for them,” Cruz added.

Cruz ended his statement with a warning, suggesting that under Republican control, the Senate could seek answers to the questions via subpoena.

“When Congress reconvenes in January, it is my hope that the Senate Judiciary Committee will convene hearings–with subpoena power, if necessary–to compel the IRS to answer these questions,” Cruz said.