Pirate radio transmitters, security systems for activist uses, etc
Pirate radio is a well-known activists re-use of civilization’s precious resources. You’d be amazed what skillful underground technicians can put together with parts pulled from old junk, plus what you can find these days on Ebay
Yes, we too use security systems. When parks have hired snipers to shoot deer, they have sometimes found the woods bugged with infra-red cameras and failed to find them all! That’s how video of these goons finishing off wounded deer by tying plastic bags over their heads got out.