A GFCI device does not need a grounding probe to protect you. If that were the case, how would the GFCI installed in your bathroom work? There's no grounding probe there. If you read Bean's article carefully you will see that there remains some controversy as to the effect of a grounding probe in our systems, whether they do more harm than good. It all depends on the equipment you have and the failure scenario. IMO a GFCI is a must to protect you, a grounding probe, perhaps. It is correct that if you do decide to install a grounding probe, you must have a GFCI as well. In either case, GFCI is the way to go for your safety.

Mike, your post made me really want to know whether or not I should have, besides a GFCI, a ground probe in my aquarium.
I finally found something that convinced me I do want a probe :mrgreen:

http://www.youtube.com/watch?v=zpBUBzk2ZIU

Imagine sticking your hand into your aquarium and you create the ground through some other piece of equipment such as a fixture, or a wet floor, or whatever.
Sure the GFCI will trip, but you will still recieve a jolt.
If your heart is healthy enough, I guess it wouldn't bother you :lol:

Forgot to mention....
In the video the plumbing must not be grounded.
Looking at our bathroom sink, I can see how the same situation would occur here as we have PVC pipes.
There is no ground wire between the drain and the pipes downstairs.