Google has lost most of a challenge to a German regulator’s order that limits how it can combine user data that would allow the company to divine customers’ personal preferences, marital status and sexual orientation.

Facebook has been drawn into the debate over the "right to be forgotten" as the social networking site will meet with a German data protection regulator to discuss jurisdictional issues raised by a European court ruling.

Google is having another run-in with European regulators over the protection of personal data.

Google shares dropped as much as 3.1% and then reversed most of the tumble within a second in a series of transactions that spurred concern the stock was hit by a computerised-trading error.

A German data protection agency has fined Google €145,000 for illegally recording information from unsecured wireless networks – an amount it acknowledged is “totally inadequate” as a deterrent to the multinational giant.