In what might be called a "soft endorsement", courts have increasingly been citing Wikipedia articles in their rulings, but usually with caution and primarily for non-essential "soft facts". The subject was the focus of a New York Times story on 29 January headlined "Courts Turn to Wikipedia, but Selectively".

Reporter Noam Cohen framed the article partly as a friendly debate between two of America's leading legal intellects, Richard Posner and Cass Sunstein. Sunstein expressed doubt that it was appropriate to cite Wikipedia in judicial decisions, something Posner did earlier this month writing for the 7th Circuit Court of Appeals in U.S. v. Radomski. Illustrating the potential pitfalls, Sunstein (working as an unregistered editor) had previously corrected a factual misstatement in Posner's Wikipedia biography. Curiously, the IP address that made this change also edited Sunstein's own biography—updating the title of his then-still-unpublished book.

Posner's use of Wikipedia was a passing reference of no importance to the substance of the case, and Sunstein conceded that this kind of citation was "too innocuous for a basis of criticism." Law professor Stephen Gillers surmised that most judges citing Wikipedia are using it as background material, not for issues central to justifying their actual rulings. The function of the citations is to provide context and make judicial opinions more readable. Given that a number of people have poked fun at Wikipedia itself for cultivating a dry, bland style of writing, the reader may wonder just how bad legal prose really is if judges are resorting to Wikipedia references to add color.

Over 100 decisions have been issued using Wikipedia as a source in some fashion. A compilation of these uses can be found at Wikipedia:Wikipedia as a court source, but the list there is hardly complete. The earliest known court decisions citing Wikipedia date to 2004, after some lawyers began using it in their court filings the previous year.

To date, the most extensive use of Wikipedia has been in the case of Apple v. Does, where the California Court of Appeal's opinion included references to 11 different Wikipedia articles. The bulk of Wikipedia citations have come from courts in the United States. A handful of citations have been noted in the courts of England and Wales, along with isolated use in such forums as the European Court of Human Rights and a German patent tribunal.