Australians have just been given a dramatic reminder of a weakness that could easily compromise the election campaign due within months.

Voters have no reason to think their political parties are robust enough to withstand a foreign hack of their computer systems in the way that undermined the 2016 US presidential election.

It is not outlandish to expect an attempt to hack into an Australian political party, find out what it knows about individual voters and use that to spread propaganda on social media like the Russian campaign in America three years ago.

It seems unlikely this year but will happen one day.