But what about all those signs that say 'Free Wi-Fi'?
IT pilot fish sets up his family's home router, and it's working fine. But soon he realizes he can improve security by limiting who gets access to his Wi-Fi.
"The router had a feature where I could lock it down by MAC address, so I ran around the house getting the MAC address for every device and entered them into the router's address table for which devices to allow access," says fish.
"I noticed one MAC address accessing my router wasn't on my list. I enabled MAC address security and that one fell off, so I was glad I locked my router down.
"It was a nice day, so I went outside on my porch. I saw my sister-in-law, who lived two houses up the street from me, shouting something and waving for me to come over.