The Wikimedia Foundation has been involved in several lawsuits. Some of them have gone in favor of the Foundation, others have gone against it.
In May 2011, Louis Bacon obtained a court order against the Wikimedia Foundation to compel it to reveal the identity of the editors who defamed him on Wikipedia. However, the order was obtained in the UK, and is therefore unenforceable in the United States.
Barbara Bauer, a literary agent, sued Wikimedia Foundation (which owns) for defamation. She claimed that a entry branded her the “dumbest” literary agent. But the case was dismissed because of the Communications Decency Act.
Professional golfer Fuzzy Zoeller, who also felt he was defamed on, did not sue because he was told that his suit would not prevail in light of the Communications Decency Act. He then sued the Miami firm from whose computers the edits were made, but later dropped the case.
In 2007, three French nationals sued the Wikimedia Foundation when an article on described them as gay activists. A French court dismissed the defamation and privacy case, ruling that the Foundation was not legally responsible for information in articles. The judge ruled that a 2004 French law limited the Foundation's liability, and found that the content had already been removed. He found that the Foundation was not legally required to check the information on, and that "Web site hosts cannot be liable under civil law because of information stored on them if they do not in fact know of their illicit nature." He did not rule whether the information was defamatory.
Sylvia Scott Gibson, author of Latawnya, the Naughty Horse, Learns to Say "No" to Drugs, sued for describing her book. Her suit was dismissed.
John Seigenthaler, an American writer and journalist, contacted in 2005 after his article was edited to incorrectly state that he had been thought for a brief time to be involved in the assassinations of John Kennedy and Bobby Kennedy. The content was present in the article for four months. Seigenthaler called a "flawed and irresponsible research tool," and criticized the protection the Communications Decency Act provided to.
The representative for the American Academy of Financial Management, George Mentz, suggested that either phony or incompetent editors were creating legal problems for Wikimedia in May 2013, because of alleged intentional false claims that had been published on.
Texas Instruments sent a DMCA takedown notice to the Wikimedia Foundation because certain cryptographic keys were made public in the Texas Instruments signing key controversy article. A editor later filed a counter-notice, Texas Instruments did not reply in 10–14 business days as required by the DMCA, and the keys were restored to the article.
In July 2010, the FBI sent a letter to the Wikimedia Foundation demanding that it cease and desist from using its seal on. The FBI claimed that such practice was illegal and threatened to sue. In reply, Wikimedia counsel Michael Godwin sent a counter notice to the FBI claiming that was not in the wrong when it displayed the FBI seal on its website. He defended's actions and also refused to remove the seal.