Last night I realized some bozo decided to point his domain name to my site. I don't know exactly what he was thinking, or what benefit he could possibly get from doing so. The only thing I could think would happen is that all my content would have an exact duplicate in Google, and we all know Google doesn't like duplicate content.
I contacted eApps,my hosting company, they contacted the owner of the intruding domain, and he refused to remove his domain name from my IP address. Tech support suggested I could set up an Apache rule to serve only my domains from my IP address.
I googled around to see how to go about this, but came out blank. Most issues I found were about preventing specific hosts to link to my site, which is not what I was trying to do. Once again I asked eApps support, and they came up with a solution.
I needed to add some rules to the Apache .htaccess file that would result in only my domains being served from my IP address:
SetEnvIfNoCase Host "mysite1\.com" local_sites SetEnvIfNoCase Host "mysite2\.com" local_sites Order Allow,Deny Allow from env=local_sites
Adding the above lines to .htaccess did the trick. The bozo is no longer serving my content from his domain.