Maybe I missed it, but the installation guides do not mention anything about using surge protection. I received an Ooma unit and installed it (without cable surge protection) and it worked flawlessly for about a week. After a severe lightening storm, the unit stopped working. My ethernet card also failed and had to be replaced. I now have another Ooma unit to replace it, but I wanted to advise anyone out there who wants to maintain reliability to use surge protection not only for your electrical lines, but the DSL or cable connection as well. Unless I am missing something, the manual should emphasize this as well.
Haven't had any issues related to the ooma, but if you have any device that is costly to replace, you really need a surge suppressor. This is true regardless of device. All of today's electronics use similar electronic components that are very susceptible to large power spikes.
I actually have a number of UPSes holding my computer, router, and other networking components (not to mention another for my TV/DVD player). In addition to providing power conditioning, the UPS will make sure I don't loose a phone connection if the power fluctuates for just a second.
And as you are saying, I fully agree. Not only your power lines but any connection from the wall to your device should be protected. Ethernet, phone, cable, or other.