Is it important to find out the religious affiliation of your ancestors? It is if you live in Egypt.
An Egyptian court has sentenced a woman to three years in prison because her father converted to Islam briefly 45 years ago. Under Egyptian law, religion is passed to children from the father.
Shadia Nagui Ibrahim, 47, a Christian, was charged with fraud for putting Christianity as her religion on her marriage certificate, even though she was unaware that her father's conversion in 1962 had made her officially Muslim. [Link]