"Is there any way...?"<p>Generally, if you mean phoning home over the internet, yes! If you mean over cellular networks, no.<p>To get things started, there should first be some "buzz" around kernelspace packet filters. Because that is what you need to start using.<p>Computers running packet filter software are sometimes called "firewalls". But that terminology does not promote much understanding among users who are not also career network administrators.<p>If you are concerned with what your device is communicating over the public internet, then you can monitor these communications first to confirm your suspicions. And then, if necessary, you can exercise some control over it.<p>How? Run packet filter software in your OS's kernel. Numerous open source, free OS's allow you to do this. And what does it cost? Nothing! With commercial, proprietary OS's that are sold for money (which are often just modified versions of open source free OS's) it may not be so easy. In fact, they may make it impossible to do. Go figure.<p>With a packet filter, you can view and, if desired, block packets entering and leaving your machine, according to your rules. Assuming you can get this set up easily (and indeed you can), why would anyone not want to do this? You can even use an old computer repurposed just to do packet filtering. Have your new devices use it as a gateway.<p>For the avoidance of doubt, popular "firewall" software like ZoneAlarm or whatever are not what I'm talking about. Those are userspace software.<p>"Can we trust hardware?"<p>In general, I'd say the more bundled it is, the less trustworthy it is. If you cannot even open the enclosure let alone run your own OS (hello Apple), that's not going to help users who want to "trust, but verify". Building your own computer (think something like RaspberryPi) gives you freedom and more peace of mind.