Internet giants Google and Facebook told the Delhi High Court on Monday that it is not possible for companies to block offensive content that appears on their websites, in a case that has stoked fears about censorship in the world's largest democracy.
Google and Facebook are among 21 companies that have been asked to develop a mechanism to block objectionable material, after a private petitioner took the websites to court over images deemed offensive to Hindus, Muslims and Christians.
At the heart of the dispute is a law passed last year in the country that makes companies responsible for user content posted on their websites, requiring them to take it down within 36 hours in case of a complaint.
The case was originally filed in a lower court, but the companies have appealed to the Delhi High Court, challenging the lower court's ruling asking them to take down some content.
"The search engine only takes you till the website. What happens after that is beyond a search engine's control," Neeraj Kishan Kaul, a lawyer for Google's Indian unit, told a packed High Court hearing on Monday.
"If you use blocks, which is very easy for people to say, you will inadvertently block other things as well. For example: the word 'sex'. Even a government document like a voter ID list or a passport has the word 'sex'," he added.
Siddharth Luthra, a lawyer for Facebook told the court it was not possible for the social network to "single out" any individual on the basis of religion or views and said the users should be held responsible for content they post.
Less than a tenth of India's 1.2 billion population have access to Internet although its 100-odd million users make it the third biggest Internet market after China and the United States. Internet users in India are seen nearly tripling to 300 million over the next three years.
Despite the new rules to block offensive content, India's Internet access is still largely free unlike the tight controls in neighbouring China.
Civil rights groups have opposed the new laws. But politicians say that posting offensive images in the socially conservative country with a history of violence between religious groups presents a danger to the public as Internet use grows.
The high court will resume hearing the case on Thursday, Justice Suresh Kait said. The judge was last week quoted by local media warning the websites of China-style controls if they did not create a means to curb material seen as offensive.