Proton, the Swiss privacy-focused software maker, says it has received a notice of a “possible block” of Proton Mail in India after the service was used in sending bomb threats to schools in the Southern Indian state of Tamil Nadu.

In a statement, a Proton spokesperson told Indian daily Hindustan Times that the firm condemns the “potential block as a misguided measure that only serves to harm ordinary people.”

“Blocking access to Proton is an ineffective and inappropriate response to the reported threats. It will not prevent cybercriminals from sending threats with another email service and will not be effective if the perpetrators are located outside of India.”

Hindustan Times reported Thursday that the Indian IT Ministry had issued a notice to local internet service providers to block Proton Mail at the request of the Tamil Nadu police. The police reported that at least 13 private schools in Chennai had received the hoax bomb threat.

D Ashok Kumar, a senior cyber crime wing police officer in Tamil Nadu, told Moneycontrol on Friday that he had sent the request to the IT Ministry to block access to Proton Mail.

Ashok Kumar, who is also the nodal officer for blocking orders in the state, said Proton Mail was “least responsive” in sharing details about the suspects who had sent the bomb threats.

“We were unable to get IP address, mobile number — other backend information of the email address because it is end-to-end encrypted. We are unable to trace them also,” Kumar said.

Proton Mail didn’t comment on Thursday. The IT Ministry also didn’t respond to a request for comment.

Many lawmakers and privacy advocacy groups expressed concerns over the possible block of Proton Mail in India. “Sources and whistleblowers often communicate with reporters using Proton Mail to avoid their identity being disclosed. Privacy is being demolished brick by brick,” Saket Gokhale, a member of India’s upper house Rajya Sabha, posted on X.

A block on Proton Mail will be the second major blow to the Switzerland-headquartered firm, which had to remove Proton VPN servers in India in 2022 in response to a local law that required virtual private network operators to disclose their customers information to New Delhi.