This EIC message brings attention to a cybercrime worse than having your identity stolen—catfishing attempts toward children while they are playing video games. Our (and parents) need be warned.

A set U of vertices of a graph G is called a geodetic set if the union of all the geodesics joining pairs of points of U is the whole graph G. One result in this paper is a tight lower bound on the minimum number of vertices in a geodetic set. In order to obtain that result, the following extremal set problem is solved. Find the minimum cardinality of a collection S of subsets of 1⁄2n 1⁄4 f1; 2...