There are several different ways someone can check up on the activities of someone else. People can purchase small cameras to hide inside their homes to observe the activities of the people they employ. A private investigator Massachusetts residents can hire, will follow someone without being observed to find out any type of information the client would like to know. This person is often hired when someone suspects their partner of cheating on them. The investigator will often obtain information and take photographs to verify what they discover about the person. Investigators can also be hired by companies to follow employees who might be leaking information to competitors.