Never judge a book by it's cover - I'm sure I've heard that saying before! - that way you get to read more books.
In England and Wales there isn't a criminal offence of "stalking". There's been a criminal offence of "harassment" since 1997.
I was on a train platform up north and some Boro fans came up to me and we got chatting. One of them said: "Do you know XXXXX" (I can't remember the name now) and I said: "No".