Recently, a warning was sent out to all Google Console users alerting them to domains and url’s that will get a “Not Secure” visible warning to your visitors.
The alert was something like this:
Starting October 2017, Chrome (version 62) will show a “NOT SECURE” warning when users enter text in a form on an HTTP page, and for all HTTP pages in Incognito mode.
The following URLs on your site include text input fields (such as < input type=”text” > or < input type=”email” >) that will trigger the new Chrome warning. Review these examples to see where these warnings will appear, so that you can take action to help protect users’ data. This list is not exhaustive.
Any page that contains some sort of form and is not running SSL encryption will show a very clear warning that users will be submitting data through an unencrypted connection.