AI war against ‘one cent’ family violence perpetrators

Artificial intelligence means many things to different people.

For some, the advent of broad language models is a threat to jobs, livelihoods, and even humanity itself.

But as Australia’s largest retail bank has discovered, AI is bringing change for the better.

A few years ago, Commonwealth Bank began receiving calls from customers warning that digital payment platforms were being misused to perpetuate fraud.

In one case, a man would send hundreds of payments for as little as a dime to smear his former partner with horrific language and threats in the payment description.

“He had blocked his number, he had blocked his social media, he had actually changed his addresses,” CBA client advocate Angela MacMillan told AAP.

“The last channel he was able to use to continue the abuse was to continually send him low value transactions.

“There were a few hundred people; I think it cost him $2.38 to send message after message.”

At the time, more than 8,000 customers had received malicious messages embedded in transactions in just three months, CBA estimates.

Since then, CBA has fed data into an AI model, allowing it to learn to block certain words, such as profanity or phrases perceived as insulting, coercive or threatening, as well as subtle expressions to avoid detection.

“It was things like ‘when are you coming home’, ‘you looked lovely in that purple jumper at the train station this morning’,” Ms MacMillan said.

The technology has prevented more than one million malicious messages from reaching surviving victims since 2020.

However, approximately 3,600 high-risk transactions per year are also flagged.

Is the frequency decreasing? No it isn’t, but Ms MacMillan says CBA blocks transactions and manually intervenes at a higher rate in high-risk cases.

“So it’s a positive … and look, it’s a symptom of the increasing problems of domestic and family violence in this country,” he said.

It’s no secret that CBA chief Matt Comyn is a great believer in the value of AI for business and society at large.

The bank, which has been training its staff for almost two years to become familiar with artificial intelligence in their daily work, has prepared its first report (Our Approach to Adopting Artificial Intelligence) on how it is embedding models in its operations.

“We aim to share our knowledge as we navigate this rapidly evolving environment,” Mr. Comyn said in a statement on Thursday.

One of the bank’s other AI wins has been in its fight against fraudsters, fraudsters and cybercriminals who target its customers.

CBA monitors more than 20 million payments through its banking app every day and sends approximately 40,350 warning alerts.

As a result, there was a 20 per cent reduction in fraud losses in the first half of the current financial year compared to the same period in 2025.

Much of this information is shared with other businesses as part of the anti-fraud intelligence loop established by the Australian Financial Crimes Exchange and the National Anti-Fraud Centre.

CBA has also built its AI model to detect malicious transactions that are available to other banks around the world.

Alex Matthews, executive director and lead author of the report, says CBA sees significant opportunities with AI but is aware of the risks.

“One of the things we’re really conscious of is Australians’ perspectives on AI… We think this is a key priority for Australia to adopt this technology so that Australia can reap the benefits of this technology,” he told AAP.

“Trust is clearly the foundation of adoption.”

Mr Matthews said it was well known that Australians were feeling cautious and the bank’s insights showed their views on AI and banking were broadly similar to their views on technology generally.

“But we are seeing promising signs,” he said.

Financial abuse victim-survivor Rachael Lloyd told the AAP CBA’s AI study of abuse transactions was “extraordinary”.

“And hopefully other banks will continue to follow,” he said.

1800 RESPECT (1800 737 732)

Lifeline 13 11 14

Male Referral Service 1300 766 491

Australia’s Associated Press is the beating heart of Australian news. AAP is Australia’s only independent national news channel and has been providing accurate, reliable and fast-paced news content to the media industry, government and corporate sector for 85 years. We inform Australia.