Government run systems should use only free software

Everyone should use only free software but governments have a moral obligation of running only free software because it does computing for the public. They run from tax-payers money. I talked with a person working in the Income Tax department and he told me that they share public's documents via WhatsApp. So even if you are careful and not running WhatsApp yourself, they might be sharing your documents over WhatsApp. I will add more points later as they come to mind. Add more points in comments. Thanks!