WhatsApp has sued the Indian government over a new internet law that would force it to make users’ messages “traceable,” the New York Times has reported. The lawsuit seeks to block the enforceability of the rules on the grounds that they’re unconstitutional. The law was passed earlier this year, but today was the deadline for social media companies to comply.

“Civil society and technical experts around the world have consistently argued that a requirement to ‘trace’ private messages would break end-to-end encryption and lead to real abuse,” a WhatsApp spokesperson told the NYT. “WhatsApp is committed to protecting the privacy of people’s personal messages and we will continue to do all we can within the laws of India to do so.”

Civil society and technical experts around the world have consistently argued that a requirement to ‘trace’ private messages would break end-to-end encryption and lead to real abuse.

India is WhatsApp’s largest market and parent Facebook rarely takes on governments in court, so the lawsuit marks an unusually aggressive action by the company. Last year, for instance, the WSJ reported that Facebook refused to take down a post from a ruling party politician even though it may have violated its own hate speech guidelines.

WhatsApp has marketed itself in India as a privacy-oriented company, but it’s fighting a separate legal case accusing it of violating users’ privacy rights. In that action, the government sued WhatsApp to force it to withdraw a policy that allows it to share data including locations and phone numbers with Facebook and its apps including Instagram and Messenger.

Last year, India banned over 200 Chinese apps including TikTok citing national security fears. Anonymous officials with several of those firms told TechCrunch that they didn’t bother fighting the bans as cases in the nation involving national security are nearly impossible to win.