You should not call people names.
Sam is in a fight on twitter with another person, and that person gets personal.
Sam wants to react to the other person.
Sam decides to block the other person, deciding it isn't worth it.
Sam calls the other person a racist name on twitter.
Sam is able to carry on with his day, not bothered by anything.
Other people find the tweet, and Sam gets fired when it gets sent to his boss.