No, there is no such requirement; an employer need not inform its workers that someone is volunteering as a condition of work release or bail. The fact is that absent legally actionable discrimination or the violation of the terms of an employment contract or union agreement, a company can set the conditions of the workplace much as it sees fit. . That having been said, if through its negligence, etc., an employee is harmed by a co-worker, the employer may potentially be held liable.