The reality we face today, not everyone phoning you will be phoning for legal business requirements. A lot of the time it is syndicates gathering information from non suspicious “suppliers”.
What they use
Signal jammer, hi jacked trucks and generally rentals.
Who are these people working for and whos at risk
Generally a larger syndicate, from TV’s, Fridges, canned foods, flip flops, electronics etc. Everyone is at risk as long as you have any form of commodity you will be at risk. Items generally get hijacked on the trucks, trailers are hooked onto another truck and the syndicates move the trailers to a “safe space” where offloading is done.