The GP clearly wrote:

"What would be wrong though is to blindly take that probability for the fact."

And it's right: your algorithms can use all sorts of indicators to flag suspicious cases, but in the end the evaluation needs to be done by a person on a case by case basis. As long as the investigation on the single case is performed "silently" (i.e. without causing any loss of time or money or any annoyance to the person who is investigated) I don't see the issue. Otherwise it's the same as saying you cannot sort rows in an excel sheet according to some criterion and start looking at the data from where it looks more promising.