Originally Posted by n5667
Flying from Athens to London to San Francisco I encountered no out of the ordinary screening.
Though Heathrow is a very interesting airport, had to go through security transferring flights going to and coming back from Athens, I think that's just due to the airport layout, however.
You will always have to go through security at a new country. If something bad were to happen, someone has to be blamed. So they need to re-screen at each country. However if you take a domestic flight to an airport like LAX where you just walk across the hall to your international flight, then you are OK. No extra security.