As dense as MacBooks are, it is nearly trivial to fit a spying device inside them, especially compared to small hardware wallets like Ledger Nanos. As secure as macOS is, once a device is inside the chassis, there are numerous ways to read data. USB serial is easily decodable, as are the many SPI, I2C, and other buses inside the machine.
Keyboard traffic is plain. Bluetooth access depends on where you are positioned. DVI is not hard to decode for capturing the entire screen. KVMs are so small now that one could easily be snuck in. Even though the motherboard is very compact, there is space above it and near the batteries.
Keyboard traffic is plain. Bluetooth access depends on where you are positioned. DVI is not hard to decode for capturing the entire screen. KVMs are so small now that one could easily be snuck in. Even though the motherboard is very compact, there is space above it and near the batteries.