Strange late night calls

I had two really late night calls from god-knows-who. One around 2:30am another 1:30am. These are strange times for me, I don't know anyone who would call me at this time. I was awake though, answered but didn't say anything and hung up straight away. But someone actually answered the second call, it was a guy (London accent, but I didn't recognise the voice), I didn't reply. I tried to get a number afterwards but it said it was an international number.

I can only put it down to two things: crossed lines OR something else: That guy I met told me someone was ringing him in the middle of the night and asked if it was me. It wasn't of course. He told me about some girl who he used to date who was kind of stalking him. He seemed to like the attention and I pointed this out and implied that he was probably encouraging it. He smiled, I think I was right. Anyway, I can't be sure, but I hope he's not taken to this calling me up in the middle of the night...we haven't contacted eachother since we last met, and I figure he figures hes scared me away with his coming on too strong.