You can gain a lot by treating terrorism as a criminal problem rather than a military or political one. You can deny legitimacy to the violent. You can forgo ill-advised military conflicts. But a bizarre case in England this week showed that the criminal-law approach has its limits. An animal-rights group called Campaign Against Huntingdon Life Sciences (CAHLS) sent a circular letter to small shareholders in GlaxoSmithKline, the £90bn ($168bn) pharmaceuticals company, threatening to post their names and addresses on the internet if they did not sell their stock within 14 days. The group objected to GSK’s ties to HLS, a laboratory that experiments on animals. The letter was frightening because other animal-rights campaigners have in recent years committed dozens of acts of bombing, assault, vandalism, defamation and even grave desecration against anyone involved with HLS in the remotest way. A British court has granted an injunction forbidding harassment of GSK’s 170,000 shareholders. It was a pragmatic move, applauded by all political parties.