Yeah, I hope this is just a demo that he is showing. You usually are fine if you have a reverseDNS domain name that you don't advertise + CF, but he is now going to get spammed by genuine human traffic.
So far I have not taken the effort to better filter them. It is a nice check to make sure the site is still working at the moment given the low volume I get.
I should try to AI inject them though at this point with something silly, like I am more likely to respond if you email as a limerick.