I debated this, but I think it's askable. I just flew transit through Beijing. Did NOT enter the country. You still have to go through security though, but whatever, it just takes time. Until I got called aside for questioning about my Anker Power Charger (this model).
Security: "What is this? It has no label"
Me: "It's a USB charger, for charging my phone, for example"
Security: "It has no labels showing how much power, it's not allowed into China"
Me: "It's not going into China, I'm only in transit! Also, where, anywhere, is there a sign saying it must be labelled?" (It had been, but was worn off)
Security: "We can keep it for you, one month"
Me: "What use is that if after a month you still won't let me take it on a flight?"
Security: "Sorry, It's not allowed into China"
Me: "It was MADE in China!"
Anyway, despite my protests, it was removed from me, as well as similar items from other passengers (I got to see a lot of them while having this discussion).
Essentially, however, I had no leg to stand on. They could have claimed my laptop computer for all I knew, and I couldn't see any way to protest, get a claim, or anything like that.
So I guess my question is - is there a way to get documentation of the event, and claim for it later, or a way to officially protest, say from the airport OR the airline, given nobody warned me they'd be looking at and confiscating power banks with worn off labels?