A ruling from the European Court of Justice has found that search engines must remove some results about individuals if they are requested to do so, under the "right to be forgotten".
The ECJ found that search engines, including Google, were responsible for the results that appear on their sites, even though the original data is first published elsewhere.
The Spanish national at the centre of the case argued that a 1991 newspaper article about him relating to social security debts was out of date, as he had paid those in full, and that references online to his past were irrelevant.
The principle has been widely labelled as "the right to be forgotten", and may allow individuals to request the removal of links mentioning their name, including newspaper reports on court cases.
The ECJ found that Google is, in certain circumstances, "obliged to remove links to web pages
that are published by third parties" when they contain information relating to a person, based on a search for that person's name.
Google said it was disappointed in the result, and would consider the implications of the judgement.
That obligation, the court said, may still exist even when there is no legal issue with the publication of the web page on the original website.
The court noted that there could be a genuine public interest in search results in some cases, and argued a "fair balance" should be sought – but offered little guidance on how such a balance should be interpreted.
They did, however, single out results where "the data appear to be inadequate, irrelevant or no longer relevant, or excessive in relation to the purposes for which they were processed and in the light of the time that has elapsed".