India has asked social networking sites and internet companies to screen and remove content which is defamatory to religious and political leaders.
Communications Minister Kapil Sibal met officials from Facebook, Google, YouTube and Yahoo on Monday and told them to screen what goes on the sites.
Mr Sibal showed them doctored photos of PM Manmohan Singh and Congress party president Sonia Gandhi on Facebook.
The companies say they cannot take action because of the number of users.
India has more than 100 million internet users and more than 28 million Facebook accounts.
Reports said Mr Sibal is particularly annoyed by the use of tampered images of Mrs Gandhi and Mr Singh on Facebook.
The minister is reported to have warned the internet sites of "stern action" against the firms which fail to act.
"These websites have been told to be more vigilant... and ensure that such objectionable matter is not used on the internet," The Hindu newspaper quoted an official of the telecommunications department as saying.
"We have asked them to actively screen and filter all such material before they are uploaded," he said.
The websites say they are unable to screen all material, but will look into any specific complaint that is raised with them.