It's perfectly legal to sniff packets traveling across your network (regardless of whether unauthorized nodes are connected) just like it's legal to have a guard dog tied up in the yard or hire a security service to monitor your house.
“It’s perfectly legal to sniff packets traveling across your network (regardless of whether unauthorized nodes are connected) just like it’s legal to have a guard dog tied up in the yard or hire a security service to monitor your house.”
Is it legally or morally ok, therefore, to send viruses to the computers stealing/sharing the bandwidth?