I'm assuming the comment "declaring martial law" would require nat guard (natives) and stationed troops (federal) to attempt to impose order. Not sure what that has to do with local infra, but the last time they tried that (LA Riots) it didn't go great. Doing it for a strictly political reason would likely result in some very hard decisions for a lot of nat guard and some federal career military. The Nat Guard and federales couldn't even restore order in South Central when most of the state was in their corner, it'd be madness to think they could handle the whole state when it was over a pissing match.
California gets roughly $162.9 billion from the fed. California pays roughly $692 billion to the fed in taxes.
It'd be pretty easy to see them choosing to just withhold whatever Trump decided to deny them and say "fine, then we'll just make up the offset, suck it", and then things would get interesting indeed.
I mean, good luck? CA is also obscenely well defended, since most of its modern wealth came from it being considered a battleground vs Japan and Russia, so there's loads of bases.
Most likely, this will just yet again be a defeat in court. That dude is just throwing shit against the wall and hoping some of it will stick.
There's also a method that was used briefly in billboards to check what radios were tuned to as cars drove by. https://www.sfgate.com/bayarea/article/High-tech-billboards-tune-in-to-drivers-tastes-2744204.php
My understanding was it mostly picked up people listening to their aux to radio adapters though.
Heck yeah! #UnionStrong