It seems that "This website is using a security service to protect itself from online attacks."
It's very easy for a security service to detect that you are using an automation tool to reach a site. If you are writing tests for the site, you might want to reach out to whoever manages the WAF behind it. I'm not too familiar with CloudFare in my own experience, but in general, WAFs have settings that can allow special users to access pages that would otherwise be inaccessible by Webdriver. You can reach out to the person who manages it, and see if there is a setting that will allow you through, such as whitelisting your IP, switching off a specific setting, or whatever. Or have them create an environment for you that has the entire WAF disabled, but perhaps is only accessible by VPN to keep the security, or allow you to build and test the site locally.
In short, the reason you are seeing this message, is because someone explicitly doesn't want anyone to use Webdriver to automate that site.