Here is the Guardian article that explains how one province in China is planting a spyware app on Android phones as travelers enter the province:
Chinese border guards put secret surveillance app on tourists' phones
Note that this is the situation Mark ( @Flyslinger2 ) referred to in the the thread
but I am sure many readers missed the point of the linked article, facing to read the post or read the linked
Hacker News article.
The conceer is that ANY nation state could plant apps on phones during border-crossing inspections. In the case of the Chinese app, it collects a wide range of data from each phone as well as searching for particular topics and phrases. Pretty nasty.
When carrying computers, a bare-naked Chromebook when crossing borders can help protect you. But, is it possible to buy a truly safe burner phone, or SIM card, in the more dangerous countries?