Currently, the private marketing system, assisted by computerization of records, generally can trace products back to their original suppliers, although not necessarily all the way to the farm. It has been suggested that a type of traceback programme might be formalised to better monitor and contain outbreaks of food borne illness. USDA has called "animal identification" an important element of any traceback system. Livestock producers already frequently identify their animals using back-tags, ear tags, tatoos, and other devices, so that incorporating animal identification into a traceback programme might not be difficult. While few dispute the usefulness of animal identification and traceback systems in general, whether they should be made regulatory requirements, or remain voluntary, is a contentious issue.