if u want to report someone, ur local game and fish is who u should call.. they will gladly help the seller "rehome" his/her fish.. but thats ur choice..
Fortunately, in the US, citizens are protected by the fourth amendment, Fish and Game or any other government agency cannot come inside your home without being invited or, of course, an emergency situation, without a warrant.
If they do come into your house without a warrant/emergence/invite then call 911 and refer to the second amendment.............