[Throw73849]

Yes, cheap devices are real problem. China has strict rules for transporting batteries that are actually enforced.

[seanmcdirmid]

Also no lighters on plane, because they know in practice they will be used in lavatories. They will find a lighter, or even just a spring from a lighter that fell apart a long time ago. Beijing airport security is quite impressive actually. They probably won't notice the knife you accidentally left your bag, however.