Acaemic Freedom is the belief that the freedom of inquiry by students and faculty members is essential to the mission of the academy. They argue that academic communities are repeatedly targeted for repression due to their ability to shape and control the flow of information. When scholars attempt to teach or communicate ideas or facts that are inconvenient to external political groups or to authorities, they may find themselves targeted for public vilification, job loss, imprisonment, or even death. For example, in North Africa, a professor of public health discovered that his country's infant mortality rate was higher than government figures indicated. He lost his job and was imprisoned. Still, academic freedom has limits. In the United States, for example, according to the widely recognized "1940 Statement on Academic Freedom and Tenure", teachers should be careful to avoid controversial matter that is unrelated to the subject. When they speak or write in public, they are free to express their opinions without fear from institutional censorship or discipline, but they should show restraint and clearly indicate that they are not speaking for their institution. Academic tenure protects academic freedom by ensuring that teachers can be fired only for causes such as gross professional incompetence or behavior that evokes condemnation from the academic community itself.