In 2013, Gary King, Jennifer Pan, and Margaret E. Roberts published research based on large-scale sampling of posts on a variety of Chinese social media, arguing that the primary motive for censorship is to quash potential for collective action, and not prevent criticism of the government "per se". Through regular, automated sampling of extant posts, the authors were able to analyze which were deleted over time. While drawing only from Internet-based sources, King et al. argued their data demonstrated that "despite widespread censorship of social media, we find that when the Chinese people write scathing criticisms of their government and its leaders, the probability that their post will be censored does not increase. Instead, we find that the purpose of the censorship program is to reduce the probability of collective action by clipping social ties whenever any collective movements are in evidence or expected."