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The promise a decked out smart home offers us is futuristic convenience. Everything from our thermostats to our porch lights bends to a single voice command, and many people have embraced it. When we buy a new smart display, however, it'd be wise to remember that we don't always own 100% of the tech, and that having the physical device in hand is only part of the equation. Why? Because the brains behind these gadgets often aren't inside their plastic casing, but rather in faraway data centers, and that can lead to certain problems.

Many smart home gadgets depend on cloud servers to run and are just hollow shells without their internet connection. They don't process your commands on-device — instead, they send your request across the internet to a far-flung server that then processes the request and sends the instruction back to your device to execute.…