A few years ago I was selling my car on a local classifieds site. I had a few interested buyers and passed on my mobile number to arrange viewings. There was the inevitable time wasters but the car sold quickly and that was that. Or so I thought. A couple of weeks later I started to get plagued with nuisance calls. Accident helplines, scams, insurance at all times of the day and night and the incessant calls drove us up the wall. I can not switch my phone off at night as I needed to be contacted in case of emergencies at work. Changing the number I have used for over ten years was a nightmare scenario I did not want to even consider..