Birth tourism
Some countries do not allow their citizens to renounce their citizenship or only if the citizenship was acquired by birth there to non-citizen parents. In Argentina, Brazil, Ecuador, Peru, and Uruguay, voting is compulsory for citizens. In Bolivia, Brazil, Chile, Colombia, Cuba, Guatemala, Paraguay, and Venezuela, military service is mandatory.
Biometrics
There are also numerous countries applying biometrics for voter registration and similar electoral purposes. According to the International IDEA’s ICTs in Elections Database, some of the countries using (2017) Biometric Voter Registration (BVR) are Armenia, Angola, Bangladesh, Bhutan, Bolivia, Brazil, Burkina Faso, Cambodia, Cameroon, Chad, Colombia, Comoros, Congo (Democratic Republic of), Costa Rica, Ivory Coast, Dominican Republic, Fiji, Gambia, Ghana, Guatemala, India, Iraq, Kenya, Lesotho, Liberia, Malawi, Mali, Mauritania, Mexico, Morocco, Mozambique, Namibia, Nepal, Nicaragua, Nigeria, Panama, Peru, The Philippines, Senegal, Sierra Leone, Solomon Islands, Somaliland, Swaziland, Tanzania, Uganda, Uruguay, Venezuela, Yemen, Zambia, and Zimbabwe.