As the message says, either your computer or a computer on the same network / ISP as yours was sending lots of spammy requests to CloudFlare. So they ask you to solve a CAPTCHA to prove that you're not part of the bad guy's botnet.
Thanks Gavin. I figured out that for some reason my VPN service was causing the message. I suspected that at first, but using the same VPN from another computer on my network trigger that warning.
I just shut off the VPN and was able to access the Bitcoin Foundation site no problem. I thought I had eliminated that variable earlier today, before I posted, but I guess not.