(CNN) Joaquin "El Chapo" Guzman's violent past warrants keeping the identity of potential jurors at his September trial a secret, according to a federal judge in New York.

US District Court Judge Brian Cogan ruled this week that the names, addresses and places of employment of prospective jurors will not be revealed; the panel will be transported to and from the courthouse by US marshals; and jurors will be sequestered from the public while in the courthouse.

Anonymous juries are rare because the US judicial system is built on the principal of transparency, says Adam Benforado, a professor at Drexel Univesity's Thomas R. Kline School of Law. Secret juries are primarily used in terrorism and organized crime cases.

The first anonymous jury was selected in the 1977 trial of a violent drug kingpin named Leroy Barnes in New York City, according to the Reporters Committee for Freedom of the Press.

Here are other examples, based on CNN reporting and federal prosecutors in New York: