The fact that it isn't worth the effort to steal it? I mean, it's a nice demo, but it has to be better than that to be useful. They say it needs planks all around the work zone. That could be solved with a camera placed at some height. What if the soil has small ditches, as it is the practice when planting? It needs nice level soil to work, as well. It's not using computer vision, or not an advanced form of CV to distinguish good from bad plants. So it requires manual identification for each plant. In my opinion, it's not ready for prime time yet.

The law?

CCTV cameras, my dog, my grandma.