Social media giant X Corp has been fined $650,000 after it failed to properly respond to an Australian safety notice about child sexual abuse material.
The Federal Court penalty, handed down on Thursday, comes more than three years after the eSafety Commissioner first issued the notice to the US-based company.
The February 2023 notice asked the company - known then as Twitter - to prepare a report on its compliance with basic online safety expectations around child sexual exploitation and abuse material.
Twitter merged into X Corp on March 15 and the company then provided its report to the commissioner on March 29.
But the commissioner identified unanswered questions in the report and wrote back to X Corp on April 6 to seek further information, which was ultimately provided on May 5.
The commissioner took X Corp to the Federal Court, arguing it had contravened the Online Safety Act between March 29 and May 5 by not properly responding to the safety notice.
The company initially challenged the accusations in court, claiming it did not have to comply with the notice because Twitter stopped being a company after the merger.
But Justice Michael Wheelahan rejected that claim and found in the commissioner's favour in October 2024, ordering X Corp to comply with the notice.
The decision was upheld by the full Federal Court in July 2025 after X Corp tried to appeal the ruling.
The US-based company on Thursday admitted the contraventions but noted they had happened at a time when there was significant corporate changes due to the merger.
The parties agreed to a $650,000 penalty, which Justice Wheelahan imposed.
The judge found it was appropriate to impose a penalty close to the maximum available fine of $687,500.
"A penalty near the maximum is appropriate in the case of the respondent, which is a substantial corporation so that it operates as a real deterrent and is not simply a cost of doing business," he said in his written reasons.
X Corp has also agreed to pay $100,000 to the commissioner for its legal fees.
The commissioner welcomed Thursday's ruling, saying it was important international companies complied with Australian regulations.
"Meaningful transparency is critical to holding technology companies to account," eSafety Commissioner Julie Inman Grant said in a statement.
X Corp will have 45 days to pay the penalties.
