Some of the newer ones have GPS tracking. Seems like to me would be a lot of cable laying around all the markers. The ones i have seen in operation have small lawns and cable run around the borders of the lawn about 2 inches under turf.If it doesn't hit a big piece of rock. Me neither.
But I wonder how long until someone takes off with the mower. Nothing is safe these days, not even in a cemetery. And grave decorations might really take a beating.