Masameer (which means ‘nails’ in Arabic) is a series of cartoons posted on YouTube. Each cartoon addresses, in a manner that is both jocose and analytical, a critical issue that shapes the everyday life of residents of the Kingdom of Saudi Arabia. Masameer exemplifies not only the views of humour by those who practice and consume it, but also its boundaries within a society both immersed in tradition and forced to respond to calls for change. In the present study, Masameer is used as a tool to understand the practice of humour, from the viewpoints of both producers and users. Guided by the principles of thematic inquiry, the analyses of viewers’ reactions to selected Masameer videos are based on four conceptual categories: overall attitude, specific references to content, orientation and connotation of expressions and analysis/interpretation. Results indicate that most audience’s responses to the issue(s) raised by each video are relevant to its content and exhibit positive sentiment. Although videos succeed in focusing their viewers on content-relevant issues and matters (as demonstrated by the preponderance of relevant comments), they fail to engage a large segment of their viewers in critical analyses of such issues and matters. These findings are interpreted as illustrating the limits of this medium as a device for either fostering social change or merely measuring it.