This paper addresses problems with swearing on the internet. The opening section of the paper defines swearing (uttering offensive emotional speech) as a ubiquitous form of impolite human behavior. Swearing can occur wherever humans communicate with each other and that it appears in computer-mediated communication (CMC) is not surprising. The second section documents how swearwords appear in email, blogs, Twitter, MySpace, Facebook, and YouTube and in other practices and sites (trolling, 4chan). Swearword use is situated in the context of emerging research on impoliteness and moral order (politeness norms and standards that govern internet behavior). Online swearword use is a function of moral order, as well as users’ interpersonal characteristics such as age (younger more likely than older users), gender (men more likely than women), the time of day (later in the day and evening), and a website’s social composition (adversarial and male dominated more than homogeneous friendly sites). The paper concludes with suggestions for dealing with internet swearword use where regulation is desirable and feasible. Websites and communities should develop moral order norms that at a minimum restrict illegal forms of speech (e.g., credible threats of violence, workplace sexual harassment).