The potential for harassment is greatly ameliorated by the fact it's the caller who pays -- receivers don't pay anything in the UK, ever. And while you're haras

The potential for harassment is greatly ameliorated by the fact it's the caller who pays -- receivers don't pay anything in the UK, ever. And while you're harassing, you can't use your phone. I don't think I've ever heard of anyone being harassed in this way. A few pranks, maybe.