Exactly. They tried in 10,000BC (causing the sinking of Atlantis), now it has re-appeared again, they want it!
The shrinking ray works by Pneumonihilizing Tenseo-stimulation, as anyone with a Doctorate in Specualtive Physics will tell you. Bombarding a subject with the right wavelength of Aetheric Flux (itself a result of the application of galvanic pressure on the Luminiferous Aether, for instance through the use of Aetherium/Unobtanium oscilators) makes all the matter in the victim's body crowd more tightly together (called 'Gravetic Densification'), making them smaller. As the name suggests, it also (through conservation of matter and energy) makes them denser (but not heavier).