Bonfire night.
Remember, remember the 5th of November.
In 1605 Guy Fawkes attempted to blow up the Houses of Parliament. He almost succeeded, but was caught. Where he was promptly tortured and executed for treason.
In 2004 people are still trying to blow up the Houses of Parliament. Has much changed? Not really, just there is more media about it these days.
Great Britain, England, Old countries of the former, has been at war for most of it's existance. In the days of old, before the first King of all England, neighbouring kings waged war. Vikings and what-not invaded. Then when England was a single country, there was war between the Welsh and Scottish.
Then finally, war with the rest of the world. The sun never sets on the British Empire... How did we get this? By waging war. Throughout all of this, people have, obviously, wanted to cause harm to the British people. In the 80's and 90's the IRA was the big thing. There was the embassy siege where the existence of the SAS became apparent.
Why are we so scared about terrorists now? The threat has always been there. It's just now the media can hype it more these days. Even if they don't mean to, they do. It's all about making an impact on the story. "Hostage executed in Iraq". No, instead it goes on for weeks with videos and emotional pleas on TV. When somebody is executed the country is plunged into shock. I wouldn't like to guess how many people were executed by the English - 'legally'. The current death penalty in the UK (only thing it applies to is high-treason AFAIK) is hanging. Not the nicest. Although then we have done a lot of beheading which is what we condemn from our comfortable position as one of the most developed (and oddly most sinful) societies in the world. Lucky it's not hung-drawn and quartered.
The odd thing is though, you ask most the people who were out on Bonfire night what it was about. Everybody knows it's tradition, but not so many people know that it's remembering a failed terrorist attack.