I’ve been really busy the last few weeks – the usual effect of the academic year starting! I’m running a new course called Maths at Work which is about how maths gets used in the “real world”. One of the projects for this involves the mathematics of networks, such as Twitter and Facebook. As part of my investigations I came across a use of Steiner trees in fraud detection. The University of Alberta press release called Math tree may help root out fraudsters gives the non-mathematical side of the story, the mathematical side can be found in the paper Social network meets Sherlock Holmes: investigating the missing links of fraud. It would be interesting to see if this actually works! Anybody have any...