Reddit has filed a lawsuit in Australia’s High Court seeking to overturn the country’s new social media ban for under-16s, arguing the law unlawfully interferes with free political communication implied by the constitution.

The San Francisco-based company said the ban should be declared invalid, or alternatively that Reddit should be exempt because it does not meet the legal definition of a social media platform.

The case, filed just days after the world-first ban took effect, names the Australian government and Communications Minister Anika Wells as defendants.

Reddit’s challenge significantly escalates opposition to the policy, adding the weight and resources of a $44 billion Silicon Valley company to what is likely to become a lengthy legal battle.