https://transparency.wikimedia.org/privacy.html
The community shares threats with the Foundation when they find them. When an anonymous poster made an alleged bomb threat, we found that the edit was made from an IP address that was near the apparent threat location. As permitted by our privacy policy, we alerted local police, passing on the IP address and details we had about the threat. The police informed us they had located and arrested the person in question, who allegedly had weapons available and reportedly confessed.
On rare occasions we discover threats against public figures. This is uncommon, but something that happens on large websites. An individual had made specific, graphic threats against President Barack Obama. This is contrary to our policies, and against U.S. law. In cases of potential serious harm to a person, our privacy policy allows us to disclose relevant information. We immediately took action, reporting the user’s IP address, user agent information, and email address to the United States Secret Service.