Sufficiently Advanced Technology...

"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke


I sadly see an arms race brewing:

TECHNOLOGY REVIEW: Today, Lu Lan at Zhejiang University in China and a few pals have actually created the first invisibility cloak designed using topology optimization. They carved it out of Teflon and it took them all of 15 minutes using a computer-controlled engraving machine. “The fabrication process of a sample is substantially simplified,” they say.

The resulting “Teflon eyelid” invisibility cloak hides a cylindrical disc of metal the size of poker chip from microwaves. But crucially, its performance closely matches the prediction of the computer simulation.

Physics arXiv:
Experimentally demonstrated an unidirectional electromagnetic cloak designed by topology optimization

Also:

Pro and Con, i.e. before I get too excited, I'd like to hedge my bets!