A 19-year-old Sydney man has been charged after allegedly using information obtained during last month's Optus data breach to blackmail people.

It is alleged the man threatened 93 customers via text messages, saying he would use their details to commit financial crimes unless they paid $2,000.

No customers paid the money.

Australian Federal Police (AFP) officers swooped on the man at a Rockdale home in Sydney's south on Thursday morning where they seized a mobile phone they allege is linked to the text messages.

AFP Assistant Commissioner Justine Gough alleged the man would have continued to send texts had he not been arrested.

He has been charged with two offences, carrying a maximum penalty of 10 and seven years' imprisonment if found guilty.

"We would allege that the offender was working their way through the list… we would suggest he was prevented from committing future harm to the community," Assistant Commissioner Gough said.

Assistant Commissioner Gough said the man was not suspected of being the individual responsible for the Optus breach but allegedly tried to financially benefit from the 10,200 stolen records that were dumped on an online forum.

She has warned people impacted by the breach to be suspicious of text messages, and not to click on links claiming to be from Optus, banks, police or other organisations offering to help with the data leak.

Assistant Commissioner Gough said the man was the first person who had been arrested under Operation Guardian and suspected it would not be the last.

"We are doing whatever we can working around the clock to protect Australians whose details have been released," she said.