无法使用Webdriver登录Facebook

Question

WebDriver driver = new FirefoxDriver();
        driver.get("https://www.facebook.com");
        driver.manage().window().maximize();
        driver.findElement(By.id("email")).sendKeys("ve*******@gmail.com");
        driver.findElement(By.id("pass")).sendKeys("*********");
        Thread.sleep(3000);
        driver.findElement(By.xpath("//input[@value='Log In']")).submit();
        System.out.println("Successfully login to the Facebook Application....");

以上程序无法登录Facebook。请任何人可以帮助我。