5 links have been added on this idea.
  1. The UK has panic buttons for domestic abuse victims.
    https://www.telegraph.co.uk/women/life/duchess-cornwall-hails-magic-secret-panic-alarms-domestic-abuse/

  2. This has been done in India. Public buses are equipped with panic buttons to help curb sexual assaults.
    https://www.aljazeera.com/news/2016/6/3/india-orders-panic-buttons-for-women-installed-on-buses