The American criminal justice system has traditionally made the identities and addresses of jurors known to the judge, the prosecution, and the defense. That tradition began to erode with the unprecedented sua sponte trial court decision to use an anonymous jury in the case of United States v. Barnes, a highly publicized criminal trial of notorious organized crime figures in New York City. Since "Barnes," Federal prosecutors in New York have requested and been granted anonymous juries in a number of similar cases, a development which has generated criticism. This article first addresses the issue of whether juror anonymity violates a defendant's sixth amendment right to a jury trial by adversely affecting the defendant's ability to exercise effectively peremptory challenges during voir dire. It also discusses the effect an anonymous jury may have on the presumption that a defendant is innocent until proven guilty. Also considered are attempts by trial judges, through particular jury instructions, to minimize or eliminate prejudice to defendants resulting from the use of an anonymous jury. The article recommends that if an anonymous jury is being considered, the burden should be on the prosecution to show that juror anonymity is warranted by a genuine threat to juror safety. The prosecution should also be required to show no less restrictive alternative for juror protection is available. In multi-defendant cases, only those defendants for whom juror anonymity is appropriate should be tried before an anonymous jury; other defendants should be severed from the case and tried separately. 113 footnotes.