Small business owners who tell customers to wear face masks and sign in using QR codes are being targeted with unfair online reviews.

Anti-vaccine and anti-mask customers are leaving scathing anonymous reviews.

The Age reports there is even a blacklist of boycotted businesses on messaging app, Telegram.

Defamation lawyer for Matrix Legal, Mark Stanarevic, says false reviews can have a devastating impact on small businesses.

He’s dealt with business owners who are in tears over false negative comments.

“If they’re false and anonymous, and there’s no credence to the review, a small businessperson can dramatically suffer,” he told Ross and Russel.

Mr Stanarevic said the first thing anyone who has had false reviews left should do is contact the review provider, such as Google. If that fails, contact a lawyer.

“These online providers, such as Google, they have too much power,” he said.

Press PLAY below for more advice on what to do if your business has been impacted