It looks like that's done at China's borders. Most journalists and tourists fly directly into China.

> but they will just ignore you if you're not brown.

It's not Xinjiang, but, as an obviously foreign Westerner, I was waved through the security checkpoints around Tiananmen Square. The setup was geared towards Chinese National ID cards, and the guards didn't want to bother with my passport. The main reason for that was probably laziness, but maybe a secondary reason was the goal of the security was mainly to control the domestic population for political reasons, and foreigners don't figure into that goal.

... crossing the border from Kazakhstan. It's not surprising for border checkpoints to have heightened security. If they had traveled by plane like actual tourists, it would've been less of a hassle.