My first V.P.N. was shut down by the authorities after three months. But back in 2011 and 2012, it was easy to find a new ladder. I could ask on Weibo for help: People would send anti-firewall software solutions to me directly. If I got in a real bind, friends would help me install new software. By 2014, I had set up six different ladders.

By my count, of the world’s 30 most visited websites, 16 are inaccessible in China, including Facebook and Google (Yahoo and Bing are available). In some cases, such as with Google, the web companies are not willing to cooperate with the government’s surveillance program. Many web services are blocked, it seems, for no other reason than that they are foreign.

Blocked websites nearly all have Chinese counterparts. For search, instead of Google, there’s Baidu. If we can’t get on Twitter, we can use Weibo. There are plenty of domestic platforms to share personal photos and videos. The government hopes to foster an Internet society that doesn’t concern itself with politics or current affairs. It has been largely successful, but the firewall and its architects still infuriate a large part of China’s online population.

Everyone — young, old, southern, northern — hates the “404 Not Found” error message. When it appears, many curse the father of the Great Firewall, the former chief of the Beijing Post and Telecommunications University, Fang Binxing.

In recent years, the word “wall” has been used creatively. If your Internet account is canceled, it has been “walled.” If you are arrested, your freedom curtailed, your posts deleted, these can also all be cases of being “walled.”

Plastered all across China this summer are propaganda posters with the slogan “Why is China strong? Only because of the party.” The Chinese word “strong” (qiang) is a homonym of “wall,” which inspires subversive people to render the slogan as “Why is China walled? Only because of the party.”

I have now gone through eight V.P.N.s. No one seems to know why or how a V.P.N. is shut down. It might be working normally one day, and the next, it’s down. You might think it is just another temporary stoppage, but after many attempts to get back online, you realize that your V.P.N. was blocked.