I've watched lots of 'No Kings' protest videos today and found no evidence of mass-produced , matching signs that

[Retrograde]

3. Antifa is very clever

they mass produce signs that look like they're handmade, just to fool people. They make them at secret printing presses in the basements of pizzerias.

Seriously, have Bondi and her ilk never heard of copy shops? I hear these days you can even given them an electronic file and they'll make signs in whatever size you want! And then you can go to a nearby hardware store and purchase lath, sticks, and staples to put the signs together. No Soros needed.