You’re going along, reading a judge’s opinion or a brief in a case, following the analysis or the argument, when a citation stops you cold. Not just any citation. But a citation to Wikipedia.
“Uhh, ok,” you think to yourself. “Why is there a cite to Wikipedia? They couldn’t have done any better?” Skepticism is not something that I would assume is helpful to your case when you create it in the mind of a legal reader.
I am far from a Wikipedia hater. While I haven’t ever edited a Wikipedia article, I’d say I use it fairly often to get a handle on basic information. But the aspects of Wikipedia that make it a strong resource for basic information can make it a troubling resource in a legal setting. Many commentators and judges have pointed out that relying on Wikipedia in a legal setting is concerning 1] because the open edit nature of Wikipedia means that information can be changed quickly, and 2] because of the sometimes “dubious quality” of the information in some Wikipedia articles. See Lee F. Peoples, The Citation of Wikipedia in Judicial Opinions, 12 Yale J. L. & Tech. 1, 3 (2010).

Potentially more authoritative than many Wikipedia articles. ""The Iraq War: A Historiography of Wikipedia Changelogs" is a twelve-volume set of all changes to the Wikipedia article on the Iraq War. The twelve volumes cover a five year period from December 2004 to November 2009, a total of 12,000 changes and almost 7,000 pages."
Joseph L. Gerken, a reference librarian at the University of Buffalo Law Library, surveyed the various ways in which courts have cited Wikipedia in judicial opinions, and found that citations to the online encyclopedia were often innocuous, whether it was used as support for a quip or other dictum, to fill gaps in the record due to a case’s procedural posture (like in pro se civil rights cases), to clarify medical facts and religious practices, decoding police jargon, or in clarifying terms used in Social Security cases. Joseph L. Gerken, How Courts Use Wikipedia, 11 J. App. Prac. & Process 191, 193-99 (2010).
So when, if ever, would it be appropriate to use Wikipedia in a judicial opinion? Perhaps a better question is to ask when it should not be used. Peoples notes several situations in which a judicial opinion should not use Wikipedia:
- Wikipedia shouldn’t be used to take judicial notice of certain facts, because those entries cannot meet the requirements of Fed. R. Evid. 201.
- Wikipedia shouldn’t be used as the only basis for a court’s holding, reasoning, or logic.
- Wikipedia probably shouldn’t be used for sua sponte or ex parte research into facts of cases before judges.
- Courts should not accept Wikipedia citations regarding a material fact in the context of a motion for summary judgment, because of the possibility of opportunistic editing.
- Wikipedia shouldn’t be used when a more authoritative source for the information can be found. Peoples, 12 Yale J. L. & Tech. at 28-30.
Peoples thinks that courts could use Wikipedia when a party relies on a Wikipedia article and discussion of it would be appropriate; to help define a variety of words like new slang terms, pop culture references, and technical and computer terms; for evidence of common usage or plain meaning of a contract term; for determining current community standards or public perception in trademark cases; to assess the substance of expert testimony; to use as a jumping-off point for other sources; and last, to assist in discussing a collateral matter that is not central to the case. Id. at 31-33.
Gerken agrees that in general, some citations to Wikipedia in judicial opinions may be permissible. Next time, a look at the questions he’d want courts to ask.