For more than a decade, the Critical Art Ensemble, a US-based art cooperative, has used scientific tools to produce commentaries of the ways science and capitalism are shaping modern society. But has their latest act gone too far?

The ensemble, whose past theatrical roles have included a biotech firm and a cloning cult, recently assumed the trappings of a military germ-warfare research team. While teaching the history of germ research in the United States, they subjected their audience to a fake anthrax attack using real, but benign, microbes.

The show was meant to provoke public discussion, but it may have also provoked a federal anti-terrorism task force. As reported on page 690, a federal grand jury will convene on 15 June to decide whether Steven Kurtz, one of the group's founders, has broken US bioweapons laws by possessing laboratory equipment and biowarfare literature reportedly used in the ensemble's performance.

On hearing this news, many researchers' first inclination may be to shrug their shoulders. Since 11 September 2001, scientists have worked overtime to ensure that their labs comply with federal bioterror laws. If an artist is running a mini-laboratory out of his home and reading up on bioweapons, it seems obvious that he would attract the authorities' attention.

True enough, but the draconian way in which the prosecutors are acting is unwarranted. Supporters of Kurtz's group say that it consulted regularly with scientists to make sure the shows were safe, and it is clear from the ensemble's past performances that no real attack was planned. As with the prosecution of some scientists in recent years, it seems that government lawyers are singling Kurtz out as a warning to the broader artistic community.

Kurtz's work is at times critical of science, but researchers should nevertheless be willing to support him (see http://www.caedefensefund.org/support.html to find out how). Art and science are forms of human enquiry that can be illuminating and controversial, and the freedoms of both must be preserved as part of a healthy democracy — as must a sense of proportion.