Web browsers make it very easy for a user to know if a webpage with a form (that includes password and credit card fields) is on a non-secure connection. The alert is meant to prevent users from entering sensitive information that could be compromised upon submit.
At the end of February, Google posted the Finding More Mobile-Friendly Search Results announcement on their Webmaster Central Blog. While the search engine has always made mobile-readiness and easy access of information a priority, it will use mobile-friendliness as a stronger ranking signal than ever before. Google’s goal is to reward websites that are mobile friendly by giving them a “boost.”