cleavage太变态了,茅斯运动的轨迹都收集 One advantage that Google has over other companies is huge amount of data. That data also includes the way you move your mouse on the screen. The way a human moves the mouse before checking the checkbox can be distinct from how a program (a bot) checks a checkbox. It's a game of prediction. Somehow, Google needs to predict whether you are human or a bot from what you do on their site. So first a system needs to be trained to predict whether the user is human or not. For this you need training data (which Google has plenty). That data includes sample movements of mouse made by humans as well as robots ( programs). Using this training data, a predictive model is made. So when you move your mouse to check the checkbox. That movement is an input to the model and based on that it's predicted whether you are human or not. If you are then fine, otherwise the same old method of filtering humans through a distorted image is used.