The problem is connecting to house wiring has to be done properly. I have had VOIP devices connected to my house wiring since 2002 with not one failure from electrical surge. I have had the HT-502 for 5 years with no problem. My property has been hit twice by lightning and travel down the underground power lines into my house which destroyed 3 electronic devices once. None of my Internet devices were damaged that were protected by surge protectors and further by UPS. Of course a lot of the energy went to the house ground before finding its way inside the house, as no surge protection can overcome a direct lightning strike. However, if my outside phone line was connected the energy would have found it's way to the phone system as the phone system is grounded thru the house ground. Since most surge protectors shunt the surge to ground, it can find it's way to anything that is sharing the same ground. Just sharing my experience.