How to Block a New Refrigerator From Getting Online

Every single electronic gadget is gathering information about you. And make no mistake, if it is digital, it is gathering data. My sister replaced her television because the one she had broke and she got one of these Roku TVs. I didn't even realize that it automatically connected to the wifi signal that I'm not even providing. How do I block a new refrigerator from getting online? It's all you.