Using a neighbor’s WiFi deprives the neighbor of using it at the same time, as using it diminishes capacity. This is not true of light. As the article says, u

Using a neighbor’s WiFi deprives the neighbor of using it at the same time, as using it diminishes capacity. This is not true of light. As the article says, using a neighbor’s light is “free loading”. The article doesn’t really say whether the author thinks that is stealing or not.