from last year, in Gagliardi v. Commissioner (Tax Court=):

Respondent attempted to discredit Dr. Pike by claiming her definition of "gambler's fallacy" was incorrect. Respondent relies on a definition of "gambler's fallacy" he obtained from Wikipedia. Respondent did not call any witness, or expert witness, to counter Dr. Pike's conclusions. Respondent's reliance on a definition of "gambler's fallacy" found in Wikipedia[18] is not persuasive. Dr. Pike and Mr. Nicely, a second expert witness whose testimony and opinions are discussed in greater detail infra, credibly explained that there is a difference in the definition of "gambler's fallacy" depending on the field of study -- e.g., psychology versus mathematics. We find Dr. Pike to be credible and rely on her expert opinion.

[Footnote 18:] Although we conclude that the information respondent obtained from Wikipedia was not wholly reliable and not persuasive in the instant case, we make no findings regarding the reliability, persuasiveness, or use of Wikipedia in general.