Yes, we can block all visitors from certain countries or force them to solve a captcha if you wish using CloudFlare settings. However, we don’t really recommend this as sometimes it can cause false alarms and block your legitimate users (i.e. if they are traveling, moving, or etc). It’s overall pretty reliable, but simply not necessary. As CloudFlare intelligently protects your domain from major hacking attempts, DDOS, and so forth, its better to not “risk” blocking real human visitors or even Google robots, etc accidentally. If possible please avoid considering country blocks, but if you feel its necessary just send us a request and we can do it free of charge.