Europe's top judges will today hear a landmark case to determine people's "right to be forgotten" online, in a battle to determine whether personal privacy online is more important than public interest.
The "right to be forgotten" could censor search engine Google, Bing and Yahoo in Europe, banning them from sharing people's personal information online if they have been asked to erase it. It is also likely to impact social media sites like Facebook and Twitter.
The European Court of Justice will determine what type of information should be removed from search engines that operate in Europe, and whether it should apply worldwide.
Should the ECJ rule in favour of France's data regulator, the Commission Nationale de l'Informatique et des Libertés (CNIL), that brought the case forward against Google, will force search engines to delist data that is linked to a person's name.
Wikipedia owner Wikimedia, Microsoft, and activist groups Reporters Committee for Freedom of the Press and Internet Freedom Foundation are backing Google.
Google is seeking to overturn a 2014 ruling in Spain, which allowed for the permanent removal of information that people consider out of date or embarrassing.
The original case was brought on behalf of Spaniard Mario Costeja González, who claimed that an "irrelevant" news article about his insolvency in 1998 appeared at the top of Google's search engine results years later. Spain's data protection agency, Agencia Española de Protección de Datos rejected the complaint against the publisher, but demanded that Google de-list the information from its site.
Earlier this year, Google lost its first "right to be forgotten" case in the UK's High Court against a businessman who asked it to remove information about his conviction.
It was the first of its kind to be heard in England, and could have implications for criminals who want to remove information about a conviction from search engines.
Some 2 million requests for links to be removed from the search engine results have been made to Google since the ruling, less than half of which were successful.
The most affected website is Facebook, with 18,723 links removed.
Google said that is does not believe one country should be able to "impose its rules" on citizens of another, especially when it comes to linking to lawful content.
"Adopting such a rule would encourage other countries, including less democratic regimes, to try to impose their values on citizens in the rest of the world," said Kent Walker, Google's lawyer and senior vice president.
"But the threat is much greater than this. These cases represent a serious assault on the public’s right to access lawful information."