My wife has an acquaintance who is 100% convinced that RF emissions from her smart meter have caused her irreparable brain damage and she has been searching for a lawyer to take on the utility. No takers yet, at least none that do not demand payment up front. She claims that she can tell when driving through a neighborhood whether or not they have smart meters yet simply by the feelings she gets in her head. Before we had ours installed, she was at the house, asking me to help her (again), and I told her I had one in my shop outside to experiment with, so I was going to go "turn it on" and take some measurements with her to see what she might be picking up. What I actually turned on was a VFD I had out there, hooked up to a small motor with unshielded SO cord, which if you aren't aware, creates a somewhat powerful local radio transmitter that you can pick up if you can mess with an old analog tuner. So I used that to confirm that the VFD was on and emitting, but told her it was off, then swapped it so that she thought it was on when it was in fact off. Then to prove to my wife what a nut case she was, I mixed it up several times, sometimes it was on when I said it was, sometimes not. She believed what I told her the status was 100% of the time, not what the reality was. Being I already know that trying to talk sense to people who have already formed a relious-like opinion of a scientific issue is pointless, I never revealed to her that I was messing with her, that was mainly to get my wife off my back about trying to help her prove her case. Since the smart meter was installed here at the house a year or so ago, she refuses to visit now.
So my personal opinion is that these are not only harmless, but are actually beneficial in pest deterrence!