w_tom wrote:
The bottom line is this. Nothing is going to stop
lightning. Lightning protection is about shunting - also
called diverting, redirecting, or electrically connecting - to
earth ground. Any protector that claims to stop or block
lightning (such as in the RCD question) is simply promoting a
myth. And yet that is exactly what many people do - promote
the myth - when they recommend plug-in protectors.

I am not naive enough to think that my little "surge protector" would
save anything from a full-on lightning strike. The issue is whether one
might reasonably expect more modest voltage transients to occur on the
mains supply (and phone line) which can be safely absorbed by such a
device, and which might otherwise disrupt or destroy delicate
electronics (equipped, perhaps, with rather cheap PSUs).

I freely admit to not knowing the answer. Your contributions make good
points about the requirements to be met in order to achieve 'proper'
surge protection, but do nothing to address this question.