As the Muslim population grows throughout Europe I'd say the biggest threat in decades to come is the Muslim factions bringing their religious wars here...They've been at war with eachother for centuries in their home lands and it's inevitable it will spread throughout the world.
Do people really fear extremist attacks?
I certainly don't and I doubt most do....more chance of a coconut dropping from an apple tree than getting killed in a terrorist attack,but saying that more extreme frequent attacks may well happen.
Saying that when its your time it's your time end of