The Uniform Evidence Acts and other Evidence Acts that operate in States (e.g. Queensland) that don't use the Uniform Evidence Act conditionally allows Facebook posts and other social media information, as documents, to be relied on as evidence.
You may review the following presentations for further information:
Not only can social media content be used as evidence,
but deleting content, changing privacy/ visibility settings,
blocking users, or tampering with hardware
to confound access to them could (subject to many ifs and buts) be an offence.
My girlfriend's ex has hacked into her Facebook messenger and was observing our life and private conversations for couple of months. He was also stalking and harassed her with the information he got from the messenger and we had no choice and reported everything to the police.
He was formally issued with an AVO for one year for doing this. Next month, there is a court hearing in regards to shared custody for their 5years old son and my girlfriend's ex attached with his affidavit our conversations printed out of my girlfriend's messenger while he had access to it.
My question is, can such an evidence be used by him in the court even if he got this illegally by breaking the law and is on current AVO for doing this? Can we appeal to the court under privacy Act 1988?
If it has been acquired illegally, then the court is unlikely to admit it as evidence, but in family law cases, the usual rules of evidence don't apply. The court may accept it into evidence if it is deemed significant to the case, but this is not often the outcome. You can argue to have it struck out on grounds it was attained illegally.