The problem is that in doing so his department is also targeting vulnerable people, thousands of whom have done nothing wrong. More than 217,000 notices were issued by the robo-debt system between July and December last year. The so-called "initiating letters" were generated by a computer program that compares a client's information on the department's files with data at the Australian Taxation Office. More than 36,000 of those letters did not result in any debt to Centrelink. What's more, about 6600 welfare recipients first learnt of their alleged debt from debt collectors. Mr Tudge blamed those people for failing to update addresses on their Centrelink files. While his department head Kathryn Campbell claims the system has been adjusted to reduce that risk, she also blamed welfare recipients – for not replying to the initiating letters.

Worse, Ms Campbell said she would not discuss potential solutions to systemic flaws with the Australian Council of Social Service or unions representing staff who have to handle the backlash. The justification Ms Campbell gave for not meeting with unions or ACOSS was that the media was interested in the issue. The justification Mr Tudge gave on ABC radio was that unions and ACOSS "frankly have a philosophical objection" to widespread compliance checks. The Herald suspects Mr Tudge and his department have a philosophical objection to legitimate public scrutiny. Thank goodness the media are holding the department and the minister to account because, failing that, thousands of people would be demonised in secret and there would be no Senate committee inquiry exposing the flawed process. The committee began public hearings this week into the error rates of debt notices; the government's response to concerns raised by affected individuals; whether the debt recovery scheme complies with Australian privacy and consumer laws; and the adequacy of the data matching of Centrelink and ATO information.

Deputy Commissioner of Taxation Greg Williams told the inquiry the ATO had "reached out" to the Human Services Department as flaws emerged in the robo-debt system, but was told its help was not required. "We are involved in identity matching and the provision of data, but we are not involved in the data-matching that occurs on the DSS/DHS side," Mr Williams said. "We are trying to maintain the level of integrity in the role of the ATO in this exercise." The Senate inquiry is also accepting submissions from people who have been forced to deal with the system. The first submission on the committee's website comes from a "a teacher, university lecturer and single mother who has been working part-time since my son was nine months old". She tells how the system "impacted my mental health and caused significant stress over the Christmas period. Not only did I suffer, but my inability to fully engage with family at this time also impacted them." She spent eight hours on the phone with Centrelink only to find that her debt was $0. "Apparently this was a mistake and a day later … it was up to over $1300," the submission says. "On receipt of the second letter I broke down in tears again ... it turned out I had been overpaid by Centrelink less than $1.80 a week. I am hard-working, smart and determined to fight this because I knew I reported my income to the best of my ability. There will be a lot of people who are not in the mental headspace, or have the ability to work out that Centrelink are wrong." The price of a system with insufficient human oversight and flawed safeguards is too great. The Senate committee should propose alternatives that offer taxpayers value for their welfare dollar without demonising innocent people.