Should you put these on every piece of furniture and TV in the house?
This depends on the reasons for using them. If you are trying to prevent pets from knocking over things, then just put them where the pets can get to the furniture that they can physically pull-down or knock over. For kids, it may be best to watch them first to see what areas they particularly like to go and where they like to reach. It may be necessary to put the anchors everywhere for peace of mind. It certainly would not hurt. Any items that could fall forward or be pulled forward from reaching or climbing should be secured to the wall for the best safety and assurance.