Posting anonymous reviews to defame someone is risky.
Telstra has been ordered to provide documents to a doctor so that the doctor can assist identify someone who supposedly defamed him.
Telstra did not appear at this court hearing.
This is similar to this case against Google: http://www.cyberspac.com/2020/03/google-sued-again-for-identity-of-users.html and also these cases:
Titan Enterprises (Qld) Pty Ltd v Cross  FCA 1241 (patent attorney ordered to hand over file)
Titan Enterprises (Qld) Pty Ltd v Cross  FCA 890 (written by Justice Edelman, now on the High Court)