“…As observed in Table 2, many studies have been performed on the dark web using content mining techniques only (Abbasi et al , 2008; Benjamin et al , 2013, 2014; Chen, 2008b, 2009; Chen et al , 2008c; Elovici et al , 2004; Endy et al , 2010; Fu et al , 2010; L'Huillier et al , 2010; Prentice et al , 2011; Scanlon, 2014; Simanjuntak et al , 2010; Yang et al , 2009). Some studies have used both structure and content mining techniques to perform feature selection, extraction or topical analysis (Bouchard et al , 2014; Chen, 2008a, b; Fu et al , 2010; Larson and Chen, 2009; Last et al , 2008; Patil et al , 2013; Reid et al , 2005; Zhang et al , 2010; Zhou et al , 2005).…”