It's not politicians. It's people. And, it is people who are paranoid and irrational. Politicians just have to cater to the majority opinion to get anything done.
The chance of dying from terrorism is far far lower than most other causes of death. It's a rounding error.
The other one that gets me is the painting by the media that pedophiles are going to snatch your child off the street, whilst the risk is miniscule, and most sexual abuse is by family members. It makes people afraid to live their lives.
If newspapers actually ranked news by how much it actually matters, we'd have a massively different view of the world.