To compare our model with the previous stateof-the-art classification model for escort ads, the Human Trafficking Deep Network (HTDN)<cite> (Tong et al., 2017)</cite> , we also polarize the true and predicted labels into two classes, "1-4: Unlikely" and "5-7: Likely"; then we compute the binary classification accuracy (Acc.) as well as the weighted binary classification accuracy (Wt. Acc.) The text data need to be vectorized before they can be fed into the baseline models (whereas vectorization is built into ORNN).