I figure if some bird brain on this planet don't know that a stack of painted boxes out in a field usually mean that Bees live there, then they derserve to get stung and i'll take my chances in court.
A few yrs ago i used to see signs in many car windows that said "Baby On Board", it didn't mean a thing except that the person had a baby, no one slowed down or drove any different.
the same as a Bees on Land sign would do, it just tells the world that they have bees and if you want to get stung, go over and slap the pretty boxes, if you want to watch them come and go, stand back and watch.