As explained before, social engineering is the art of manipulating behavior using specially crafted communication techniques. A social engineer is a hacker who uses brains instead of technical computer processes. Social engineers are hackers who use the weakness that is found in nearly every organization, the human factor. By using a variety of techniques and tools, a social engineer can make phone calls and use social media, or email services to trick people into delivering their sensitive information or credentials. Cybercriminals use social engineering tactics because it is usually easier to manipulate individual's natural tendencies rather than hacking computer systems or software.
Security is all about knowing who and what to trust as well as knowing when, and when not, to take a person's word.