Ordinary extension boxes offer no protection to your appliances. When you use them, your appliances are exposed to the full risk of damage from power surges, lightning strikes and myriad other power issues that can damage your appliances and devices. When you save on cost of extension boxes and end up with risk of damage to your sensitive TVs, home theater system, decoder, iPhone and other phones, laptops, printers, tablets, WiFi modems, projectors and other prized appliances, you need to think again.
Plugging expensive, high sensitivity appliances like laptops, desktop PCs, phones, TVs, etc into basic power extension boxes is not the wisest thing to do. They offer no protection against power surge, thunder, overload, and other power hazards that could damage your precious equipment.