If people have the right to delete photos and updates on Facebook or Twitter, do they also have the right to have their personal information removed from search engines? Europe has been grappling with this question in recent years, and Spain's highest court has just asked the European Court of Justice (ECJ) to decide whether requests by Spanish citizens to delete data from Google's search engine are lawful. In one case cited by Spain's court, a man is contesting the repeated appearance of an old notice about his home's repossession in Google News, even though he had resolved the dispute years earlier. The right to be forgotten is just the latest concern in a growing heap of privacy issues for web giants: some in the EU have claimed that Google is breaking European law with its new privacy policy, other companies like Apple and Microsoft have been challenged over privacy controls, and even seemingly innocuous things like cookies have been called into question.

Google tells Reuters that "we support the right to be forgotten, and we think that there are ways to apply it to intermediaries like search engines in a way that protects both the right to privacy and the right to free expression" — but there are philosophical differences in the way these rights are interpreted internationally, which could complicate the regulatory playing field for Google and other indexers. EU commissioner for justice and fundamental rights, Viviane Reding, has proposed right to be forgotten rules to the European Parliament. Reding says that "if an individual no longer wants his personal data to be processed or stored by a data controller, and if there is no legitimate reason for keeping it, the data should be removed from their system," but she also notes that there are cases where the right to be forgotten is not absolute, like in newspaper archives.