Government officials are upset about material insulting to Prime Minister Manmohan Singh, ruling Congress party leader Sonia Gandhi and major religious figures. Some illustrations have shown Singh and Gandhi in compromising positions and pigs running through Mecca, Islam's holiest city.

On Friday, the federal government told a New Delhi court that there was sufficient material to proceed against 21 social networking sites for offenses of "promoting enmity between classes and causing prejudice to national integration," according to the Press Trust of India news agency.

The cases, which PTI said name companies including Google, Facebook, Yahoo and Microsoft, represent a new risk of doing business in the nation of more than 1 billion people, which is looking to technology to boost its economy and standard of living. The dispute highlights India's difficulty in balancing the Internet culture of freewheeling discourse with its homegrown religious and political sensitivities.

Convictions could bring fines and up to five years' imprisonment, through prosecutors have named only the companies involved rather than any executives. Metropolitan Magistrate Sudesh Kumar on Friday asked India's External Affairs Ministry to serve summons to officials of foreign-based companies for court appearances March 13.