Here's what the ACCC has to say about it
"Social media gives large and small businesses a direct way to interact with existing and potential customers, and promote their products and services. Businesses using social media channels like Facebook, Twitter and YouTube have a responsibility to ensure content on their pages is accurate, irrespective of who put it there."
While it looks like "anything goes" - it doesn't. You have an obligation to act honestly and within the guidelines that protect consumers, just as you do in your business normally.
Note that this honesty of information also includes anything that OTHERS may write on your profile - your obligation is to monitor what others might be saying on your social media properties and ensuring that misleading information is dealt with in the appropriate manner.