Employer discrimination is prohibited a litany of grounds per the Civil Rights Act of 1964, specifically Title VII of the act. All states must adhere to laws preventing employer discrimination against workers, and typically, all companies that engage in interstate commerce are subject to these laws. There are some unsettled debates over discrimination in employment, which are difficult to prove occurred or simply are not illegal in a given state. For starters, federal laws do not recognize same-sex marriages or the rights of persons of same sex orientation to be discriminated against in the workplace, but most state laws provide some protection for these individuals. Other cases, such as employers accessing past criminal records, medical records legally available, or using public information on the internet regarding an employee can form an decision to terminate or not hire an employee, but in reality, are part of the public domain and almost impossible to prove. Additionally, an illegal practice known as blacklisting can virtually ruin a marked employee's career, but unless actively pursued by past employers, is virtually impossible to prove.