Is this an epidemic?? What's the philosophical reason behind this?

It seems that there are more and more car bombings and suicide bombers, people committing suicide and takings others with them. What's the driving force for this increase in what I'd call bizarre behavior. It's a non-sequitur. Some of it is religiously motivated, but others seem to madness or maybe a disease. The religiously motivated ones are a disease too. Is there a philosophical reason behind this?