Thousands of black-clad demonstrators braved tear gas and rain for 79 days in Hong Kong's 2014 "Umbrella Movement." The lessons of that agitation appear to have made the city's protesters swifter and better prepared in some of their latest attempts to weather police action.

The young citizens who crowded into the streets this week to protest a bill that would allow extradition to mainland China used the Telegram encrypted messaging app to share locations. They handed out surgical masks for protection against pepper spray and to hide their faces from the police. They turned cars and trucks into roadblocks in the middle of highways. And they set up supply stations throughout the demonstration, acting more quickly than they did five years ago.

"It's a real genius of Hong Kong people," said Kong Tsung-gan, author of "Umbrella: A Political Tale from Hong Kong." "There are no pre-existing structures, and before you know it, they're there."