In the decade I spent reporting from China, the most immediate obstacles to journalism were often physical. They took many forms: barricades blocking access to certain places; men in military buzz cuts trailing me; plainclothes thugs stationed in front of the homes of people I planned to interview; and of course, the threat of police detention.

In one memorable incident, an official threw himself in front of the car I was riding in with colleagues to delay our departure, precipitating an unseemly shoving match. These physical manifestations of state power were designed to muzzle through intimidation and brute force, occasionally reinforced with threats of visa refusal.