Panic on the streets of London

I guess by now you've all heard about the bombing in London. Luckily for me, I'm far away from London, but still there's now bomb scares all over the country, one of them in Sheffield which is the nearest city to me. Big steel city, so it's always been a major potential target. Who knows what might happen. It sucks. Thirty two dead up to now; and of course there's going to be a lot more. The police have said that they think this isn't the end of it.. of course. It's been said they haven't aimed to kill many people - they just want to shut down the entire public transport network. But if they're doing this, then why? There's obviously a reason they don't want people to be able to get around.. so they can go and do something worse. Al Qaida have apparently already owned up to it... I don't know.