[snowyskiesau]

I have three computers on my home network and they are always powered on.

Major reason is that I work in IT and some contracts allow me to work from home. When at a customer site, I can connect into my home systems if there is something I need to retrieve. On occasions, I perform remote monitoring of servers and alerts need to get back to my servers.
I run a hardware firewall than does not allow any incoming connections except via a VPN.

I do have a wireless access point for use with the laptop (and a TV set top box connection) which I have this configured for MAC address filtering. So far, no one has been able to get free internet access via the wireless connection.