Gunmen on motorcycles kill three people when they open fire on a wedding outside a Coptic Christian church in Cairo. A twin-suicide bombing outside a church in Pakistan kills at least 75 people.

These two recent headline-grabbing attacks occurred within just a month of each other. Horrific, but by no means isolated incidents.

So how widespread is anti-Christian violence?

"Credible research has reached the shocking conclusion that every year an estimate of more than 100,000 Christians are killed because of some relation to their faith," Vatican spokesman Archbishop Silvano Maria Tomasi announced in a radio address to the United Nations Human Rights Council in May.