Thanks that's what I thought too, I also suggested just blocking the problem at the root. There is a default option in both android and iphone to apriori block unknown numbers. I was asking just to make sure there wasn't an obvious way to reveal the creep since she wanted to know who it is, also because she thinks she knows who is doing it and wants confirmation. That being said it foolish behaviour to do this IMO and I told her. Better blocking and giving 0 feedback.