No terrorist is going to publicise a bombing before it happens, but that's not the purpose of the threats.

When Irish terrorists were bombing british targets, there were many, many bomb threats phoned into local radio stations. Only a small fraction were real attacks. The rest resulted in disruption to people's businesses and daily lives as people were evacuated and train stations were closed.

So long as one in every hundred threats results in a real attack, then every warning needs to be acted upon. If you took your kids to a church service in Doha, and they were injured by a bomb, you'd never forgive yourself for ignoring the warnings.

If your government received a warning of attack, but didn't warn you, and there was an attack, you'd never forgive your government, would you?

So, you see, the terrorists win simply by posting the threat. They have to do nothing more than make a false claim, and most sensible people will change their behaviour. I don't go to church - salvation through holy zombies isn't my thing - but if the threat was about a shopping centre, you can bet that I wouldn't be taking my kid there.

--nigel