There is some thematically related work, such as automatic filtering of pornographic content (Polpinij et al., 2006;Sood et al., 2012;Xiang et al., 2012;Su et al., 2004), but we believe the nature of the task is significantly different such that a different approach is required.
text or document classification, the general technique employed in this paper, is a very common task (Manning et al., 2008).