In addition to the ordinary duty of care, California statutes impose special relationships upon certain types of employers. For instance, schools owe a duty of care to use reasonable measures to protect students from foreseeable injury by third parties. This includes negligence by teachers, school personnel and even other students. Transportation network companies, such as taxis and limos, must by law conduct a criminal background check of their drivers. They may not hire a driver with a history of certain crimes, including crimes involving violence.