#PI Whether you believe it or not, it doesn't matter. Many thousands of people can chat inside the network of the old four, people from various countries can chat. A few years ago, a piece of news caused the software of a certain exchange to crash directly. Why? Because this news made all the PI friends log in, which caused the system to crash. But can the system of the old four crash directly? With so many of us logging into the network of the old four, when has it ever crashed?