1. A computer-implemented method for providing a profile of an anchor value, comprising acts of: detecting a plurality of digital interactions at different points in time, the plurality of digital interactions comprising web site and/or mobile device app interactions; for each digital interaction of the plurality of digital interactions: identifying from the digital interaction an anchor value X of an anchor type T, wherein the anchor type T is selected from a group consisting of network address, account identifier, email address, phone number, credit card number, location, device characteristic, and device identifier; and updating a profile of the anchor value X, wherein: the profile of the anchor value X comprises a plurality of counters C[i,j] (i=0,. .. , M−1; j=0,. .. , N i −1); for each i=0,. .. , M−1 and j=0,. .. , N i −1, the counter C[i,j] indicates a number of times an event E is observed during a time interval I i,j ; and updating the profile of the anchor value X comprises: analyzing the digital interaction to determine if the event E is observed in connection with the digital interaction; and in response to determining that the event E is observed in connection with the digital interaction, incrementing the counter C[i,0] for each i=0,. .. , M−1; identifying the anchor value X from an on-going web site or mobile device app interaction; using the profile of the anchor value X to generate a score indicative of a level of risk associated with the on-going web site or mobile device app interaction; and if the score is above a selected threshold, alerting an operator of a web site or mobile device app via which the on-going web site or mobile device app interaction is conducted.