Just so people don’t get a false sense of security, a shield for the tazer won’t do anything. Since the potential thief has to go for the canbus block behind the headlight switch to plug their device in, they just need to unplug the security gateway plug from that block, which will effectively unplug the tazer. It’s easy to pick out the gateway canbus connector on that block because it’s the only one that doesn’t have a yellow wire as one of its two wires.
So, once it’s commonly known that tazer has this feature, they’ll just assume that’s what they’re dealing with on every truck, and just snip those two wires first before they plug in their device.