I know this thread is super old, but the new surge protector I Just bought tonight at Ace Hardware says the same thing on it. I am betting all my others did too at one point, but I never bothered to read them, and haven't had any issues, so hopefully this one will be fine too. I did wonder though, I saw a post recently on here about a powerstrip specifically made for aquarium use that caught fire and really destroyed a home with all the damage (I want to say it was a Coralife?). So perhaps the ones specifically made for aquariums aren't any better in that aspect? I assume any will short out if they get wet - no matter if they are made for aquariums or not.
Also - I'm debating putting GFCI outlets in all locations where I have aquariums plugged in. Any idea if that is overkill or a good idea?