They have worked assiduously and skillfully in legislatures, schools, and the media to pursue their cause, and in many cases their actions have met with a great deal of success. Animal research has become more costly and difficult, in part because of self-regulation by scientists but also because of externally imposed regulations. Some animal researchers have left the field, and young researchers have chosen not to enter it. Many members of the general public have the impression, based not on facts but on repeated allegation, that too much animal research is done.

Some members of the animal rights movement pursue more extreme tactics, often with the implicit backing of more moderate elements.²⁶ Since 1980, more than 30 break-ins, thefts, and acts of vandalism against research facilities have caused millions of dollars in damage. ²⁷ Records representing years of work have been destroyed. Researchers and their families have been harassed and threatened.

The scientific community can find no moral justification for these acts, although they are excused and even supported by leaders and leading organizations in the animal rights movement. Vandalism and harassment have slowed medical research that is dedicated to improving human well-being. Individuals who vandalize laboratories and harass researchers are not only breaking the law; they are also materially harming the people who would eventually benefit from the research being done and are denying hope to those with presently incurable diseases.