India’s Supreme Court has ordered internet giants Google, Yahoo and Microsoft to block adverts for pre-birth tests that reveal a child’s sex.
Such adverts are illegal in India because of the widespread underground practice of aborting female foetuses.
This has led to a skewed gender ratio in much of India.
The court was responding to a petition that noted that gender-test adverts are displayed on major search engines despite being illegal.
Google and Microsoft had argued they were not advertising anything that violated Indian laws.
Technology writer Prasanto K Roy told the BBC that enforcing the ban would be very difficult, if not impossible. “There are so many ways to get around filters and it will block the genuine stuff. For instance, filters normally would scan the text, but they don’t stop graphics and many of the ads would have only graphics,” he said.
A further problem, he added, was that “these ads could be uploaded from anywhere in the world, targeting a specific geographical location.”