I had it done to me a few years back, they spent around £600-700 over a month or so which I hadnt noticed because I wasnt checking my bank statements properly, i just thought i was spending more than usual. When I sat down and actually had a good look they had been topping up their phone with credit, joined some dating sites and bought a plane ticket for £180. Worse thing for me is I have a good idea who it was but could never prove it, if they could have told me where the plane ticket was for it would have confirmed 100% to me who it was but by that point they had left my life and I had no way of contacting them . He was (so i thought) a good male friend who I had an intense friendship with over 3 months, I now realise they were using me , telling me lies , encouraging me to drink far to much and spend most of my time sozzled. I got all the money back though thank god.