The launch comes as Ringleader faces a class action lawsuit that accuses the company and certain users of its technology of tracking the online behaviour of mobile phone users across sites without their permission.

Among the allegations in the lawsuit is the claim that consumers are “inadequately inform[ed]” of the extent they are being tracked “by an unidentified third party”, and that “most of the defendants’ sites fail to address or identify Ringleader and Media Stamp at all”.

Ringleader CEO Bob Walczak has previously stated: “To the extent that the plaintiffs are alleging that Ringleader violated any laws relating to consumers’ privacy, Ringleader intends to defend its practices vigorously.”

The company does provide an opt-out facility on its site, but one of the publisher responsibilities listed on the Cert Centre website is that Media Stamp clients include a link to Ringleader’s privacy policy, as well as an opt-out link, in their own privacy policies.

Beyond the privacy issue, Ringleader says the Cert Centre is meant to help publishers check their technical compatibility with Media Stamp, while agencies can use it to search for publishers that use the technology to run “targeted” and “trackable” campaigns.

Walczak said: “The Certification Centre grants agencies easy access to the publishers leveraging our proprietary technology and also allows us to make sure that publishers are sharing important information about our privacy and opt-out policies with their visitors.”

Media Stamp builds profiles of mobile devices by tracking online usage patterns across “nearly 100 discriminators that include device type, geography and mobile carrier information. The technology “does not track users”, the company says, and “does not collect personally identifiable information”.