As I host a website myself, I understand the need for websites to filter certain traffic to avoid spam bots and the like. However, I find the method used here to be a bit strange, as it would be quite easy for a computer to interpret and solve. Surely something like Google's ReCAPTCHA system would be better to ensure that users are legitimate?
The only reason I am even aware of this is because a couple of the UK server's my VPN provider uses have been flagged apparently, but I am still curious as to the reason for using such a simple and possibly insecure one.