[jjgod]

> There was a mass of security theatre, X-ray machines at the entrances to some (most?) lines but lots of people were just ignoring the attendants and walking quickly passed the machines without having their bags checked.

Yes, that’s the main difference between Beijing and Shanghai’s metro system. In Beijing, there is no way to avoid security check and everyone obeys, while Shanghai didn’t enforce that and everyone learned to ignore that.

Then again, there are people arguing that the security measures in neither systems are very effective.