Muslims observing the annual Hajj pilgrimage to Mecca have taken part in the "stoning the devil" ritual. The annual ritual usually brings millions of worshippers from all over the world. But this year, only 60,000 Saudi citizens and residents that have been fully vaccinated were selected for the rite. Aside from strict social distancing measures, authorities have introduced a "Hajj smart card" for pilgrims. What's its function?