Bravo! Another beekeeper. We should all be excited about others getting bees. ;)
I thought many of my hives were "isolated" years ago. Then, when I got the master list from the state when I was an inspector, I was shocked to find out how many had hives close to my yards. If I had previously looked closer, I would of seen some of the other beekeeper's hives from my own yard. And the list only accounts for what is reported, which realizes that there are probably more locations nearby as most beekeepers have yards they do not report.
Yes, it is nice to know who is close by. But I have seen bees rob out hives from at least a mile away. So unless you know who is further down the road, worrying about the guy 200 feet away, makes little sense.
Maybe you can make a new friend, help a beekeeper (since you think he has all kinds of nasty stuff in his hive already) and actually contribute to the overall bee industry. That would be far better than casting unfounded guilt, and assuming the worst.