It is great to see robots helping human to clean windows, but it is not ok if there are too much robots. They might attack our world after they have their own opinion. Cleaning windows is a great thought of not creating dangers for people. But I wonder how steady the robot is. If there is a little mistake, the robot might fall down. It is worse than just a human cleaner fall down, because it might crash us and get many people into injuries. So we should test the robots in different ways to check. Anyways, using no soap byut just water too clean the windows is very cool!