Australians are being urged to cyber cull and pause before they post in 2021 to protect themselves from cyber criminals, fraudsters, organised crime gangs and sex offenders.

The Australian Federal Police is warning that social media users are posting too much personal and professional information, and some have become easy targets for criminals.

AFP assistant commissioner Justine Gough said the advice was for all Australians.

"You wouldn't walk up to a stranger and let them know your security clearance or that you work in payroll in your organisation," Ms Gough said.

"You wouldn't give a stranger your phone number, your date of birth or provide them with a photo album of your children.

"But too many Australians are essentially doing this by posting this information online and not turning on strict privacy controls. Pause before you post. Ask yourself, 'Do you really need to reveal your personal details?'"

Ms Gough said some Australians could be targeted because of their position within a company, government agency or university.

They may pretend to be an employer or recruiter wanting to hire and groom a victim to understand what access or knowledge they have within an organisation.

In other cases, people are putting their financial security at risk.

"Criminals are harvesting information, stealing identities and then stealing victims' money, or taking out credit cards in victims' names. In some cases, criminals have been able to obtain personal information and access financial accounts.

"People who are selling second-hand goods on websites and provide their mobile phone number can leave themselves vulnerable to phishing attacks. Personal information is a valued commodity for criminals, who can sell this on to others in forums on the dark web.

"We also know child sex offenders have looked for victims by targeting single parents on dating websites.

"We are also urging all parents to think twice about posting photographs of their kids. Some platforms do not automatically remove geolocation data from images taken on mobile phones allowing for identification of where you work, your home address or other private locations.

"The online world allows criminals to steal from, and manipulate victims, from across the globe. That's why Australians are being urged to be cyber wise in 2021, and to review and cull sensitive and personal information they have on all their social media platforms."

Online users should review location, privacy settings and parental controls and review and turn off location settings, such as GPS, when unnecessary. Ensure privacy settings are secure and set to 'Friends only' or 'Private'.

Are you careful about the information you post on social media? Do you know people who post too much personal information online?