Open Proxy Scanner

[delta5]

Years ago, I ran an IRC server, and the "services" package included an open proxy scanner. I have discovered
someone lurking with an IP belonging to changemyip.com and was wondering if open proxies are still a threat. If so,
would there be a mod available to detect this? Just curious, as Im using the Sucuri firewall, and i suppose i could blacklist
that IP or even the IP range.

Thanks,
Delta5