Changing an IP or email address to mask the identity of the person using it. The internet is a conference and people are using the wrong nametags. This can be useful when you want to impersonate a person or company to trick a third party.

This is an impersonation attack where the CEO of a company is impersonated in order to scare someone in say, accounting, to make a mistake and transfer money to the wrong account. Maybe CEOs need to be a little nicer to their employees if there is a whole tactic around using the title to scare employees into doing something without question...

This is where an attacker pretends to be someone that you know and trust in order to trick you into giving them money or information. By the way, if you're the time that will send money to your friends without asking too many questions, can we be friends?