Let's say the police installs a new device in your house. This device could be capable of seeing or hearing anything that happens in your entire home. However, the police claim that the device is only watching a specific door in your house and forwarding encrypted low resolution photos to their servers "just in case" some criteria is met and they need to take a look. Nevermind that it would only take a policy change and an OTA update that you have no visibility into, or chance of blocking, before it's watching your entire house in real-time and sending practically anything to their servers. After all, they did release a carefully worded statement regarding what the device supposedly does.
But hey, you have several other doors to enter or exit your house from so what's the big deal right? You could seal that door and never be subjected to the system _as advertised_.
Would you trust the police in that scenario, regardless of whether you have anything to hide?