Internet advertising firm Gator has filed a lawsuit asking a federal court in San Francisco to declare that placing pop-up ads on other companies' web sites does not violate the rights of the sites' operators, according to a story by Bloomberg.

Gator was recently sued by major companies, including the Washington Post and United Parcel Service, which are upset that those running Gator's software will see ads when they visit their sites which the site operators did not authorise.

It lost the first round of that case and is appealing the ruling in a Virginia court – in addition to seeking the declaration from the Californian court that its practices are lawful.

We are processing your request. \n Thank you for your patience. An error occurred. This could be due to inactivity on the page - please try again.