"Websites that help people find jobs or hospitals have been hit by legal action threatened by the Royal Mail.The threat was issued against the company supplying them, and many other sites, with postcode data.
Royal Mail said the legal action was threatened to stop "unauthorised access" to the postcode data.
Ernestmarples.com, which supplied the address data, said it did not have the resources to fight a legal battle so has turned off its feed...
Commenting on its action the Royal Mail said: "We have not asked anyone to close down a website.
"We have simply asked a third party to stop allowing unauthorised access to Royal Mail data, in contravention of our intellectual property rights," it added in a statement."