What's funny is that it's obvious to anyone who would received an email like this is that it's spam to be ignored. What makes an email like this any more believable than anything you get unsolicited by email making any claims or demand? The fact that it is mentioning DDOS instead Nigerian money? I am surprised that cloudflare feels the need to even write this up and the fact they they take it seriously is only mitigated by the marketing angle (which makes them smart instead of naive I guess).