For Australia’s banks and regulators, Square’s dramatic acquisition of Afterpay this week is not a case of the barbarians being at the gate; rather, it shows how big tech has walked right through, and is now operating deep inside Australia’s financial system.

Even before this week’s blockbuster $39 billion offer for Afterpay, Square has been busy selling payments terminals to small businesses in Australia and has quietly begun lending to SMEs. Meanwhile, the use of Apple and Google digital wallets has taken off as more Australians use smartphones to pay for things, while Facebook is working with other tech companies on a private cryptocurrency that will make it cheaper and faster to buy things online. Banks are bracing for what might come next.