Two cars loaded with explosives were discovered in the heart of London's entertainment district, but the bombs were disabled before they went off.Source
....Mr Howard says it does not heighten security concerns in Australia, but people should always be alert.
"It is a direct reminder that in a society that is so similar to ours in so many ways we can't afford to be complacent," Mr Howard said.
Car bombs and IEDs are not so hard to design, if you are only trying to penetrate human flesh. Western societies are soft targets--particularly in the UK and some other European countries, where terror suspects are often released prematurely to bomb again.
Car bombs in Pakistan, Afghanistan, Iraq, Lebanon, and other non-western countries are not viewed with surprise when skimming the papers in the morning. Car bombs in London, Sydney, or New York, instantly become front page news. Why are there so few of them?
Remember the science fiction film "Alien?" The alien creature attacked some of the crew members, but not others. Some of the crew members were incubating the future generation of aliens. Best to let them live for now.