Most of us will encounter an “everyday sadist”

http://www.psychologytoday.com/blog/the-integrationist/201408/dealing-everyday-sadists-and-other-dark-personalities

Most of us will encounter an “everyday sadist” – someone who actively seeks to cause us emotional pain. Given the potential for overlap among sadism, narcissism, psychopathy, and Machiavellianism, for the purposes of the below we will refer to anyone who purposefully causes emotional harm as an everyday sadist, or ES. The actions of an ES can range from the petty to the severe.

Common examples of everyday sadism include:

Repeating a secret that the ES promised to keep private
Portraying someone in a false or unflattering light in an effort to damage their reputation
Working to bring about someone’s being fired or otherwise jeopardize their job in the absence of cause
Seeking to ruin another person’s relationship
Theft of property – physical, financial, or intellectual
Cyber or other bullying

ESs can be very skillful at orchestrating such situations, and often set them up so that it is difficult to prove that they are culpable (they will never take responsibility or feel remorse for harming another, regardless). Because of their ability to charm others, ESs may be popular, professionally successful or socially influential, and thus, others may be either unaware or unable to acknowledge the deliberate and harmful nature of their actions.As described above, the ES may seek to harm another because they believe it benefits them in some way, because they feel threatened or envious, if they perceive the target as weak and/or unlikely to retaliate, or simply because hurting another is pleasurable. In some cases, the reason for the attack may be difficult for the victim to discern. Although we may like to think of ESs as strangers, the ES may very well be someone you know and consider yourself close to, such as a family member, friend, partner, or colleague.