He who is Andy Burns said on Sun, 29 Oct 2017 16:53:03 +0000:

I think what you're saying is that if they can get to *any* of your
devices, over the Internet, then, *from those devices*, they can intercept
your traffic to, for example, your Linux laptop or Android smart phone.

I think in your case you say your house is out of wifi range of your
neighbours; but since you're advising friends and family, it could be
that one house's fridge/camera/thermostat hacks the neighbour's wifi
traffic ...

I understand only the *basics* of that argument, which is that if you have
device 0 (the router), and then client 1 (refrigerator) and client 2
(Android phone), and client 3 (linux laptop) that *all* are vulnerable.

The basic argument is that if someone gets in on client 1, 2, or 3, then
the *whole* network is compromised.

But is it?

If client 1 is a refrigerator with very poor security, I get it that they
can hack easily into client 1.

All I'm asking is how does access to client 1 give them access to router 0
which "controls" the entire LAN?