A lot of woos like to complain that us skeptics can't come up with new ideas: That we're only able to shoot them down. Well, I intend to disprove that... Though my technical prowess is quite limited, I can assure you what I come up with will probably be bad ideas. But you never know. Something I think up might be more practical than I believe it to be.
Passive RFID tags have no internal power source: They're small enough that they can be powered by the radio waves emitted by the scanner. When I thought of that, after dealing with a wireless Playstation controller that goes wonky when the batteries start getting low, this probably bad idea came to mind: Is it possible to power something as big as a wireless controller with radio waves, using the same principle? Probably not. RFID tags probably function on very small amounts of electricity, while my controller is powered by three AA batteries.
So, first big problem: Sheer amount of power needed.
Second big problem: Interference. Since I know little about the far ends of the electromagnetic spectrum (beyond how a microwave oven allegedly works), I don't know how messy the air waves would get in my house, and I'd prefer not to have my laptop go through another finicky wi-fi phase.
Third big problem: The FCC. The jerks who shut down the pirate radio station I operated in my imagination, (La-La Land adjacent) probably wouldn't like it. As far as I know, firing the thing up might deafen the FCC guy intently listening to all the forbidden frequencies for any unscheduled blips.
Fourth big problem: Why deal with all this, when you can just use a cord or a spare set of batteries?
So, that's the preliminary rip on my own idea. It's quite bruised. All you happy tax payers out there, please commence making it bloody. Cookie for the first one who does it with precise-looking math.