The Indian government cyber snooping programme is becoming so pervasive that it makes the US Prism operation look harmless. India is giving its security agencies and even income tax officials the ability to tap directly into e-mails and phone calls without oversight by courts or parliament, several sources said.

The excuse is that the move will help safeguard national security, because that excuse is always trotted out when governments do evil things. The Central Monitoring System (CMS) was announced in 2011 but there has been no public debate and the government has said little about how it will work or how it will ensure that the system is not abused.

The government started to quietly roll the system out state by state in April this year, according to government officials. Eventually it will be able to target any of India's 900 million landline and mobile phone subscribers and 120 million Internet users.

Cynthia Wong, an Internet researcher at New York-based Human Rights Watch said that if India doesn't want to look like an authoritarian regime, it needs to be transparent about who will be authorised to collect data, what data will be collected, how it will be used, and how the right to privacy will be protected.