From a site talking about the evils of sucralose sweetener:
Splenda is approximately 600 times sweeter than sugar, but the sweetness is forced, not like a natural sugar the body uses for fuel, says Dr. Hull. And although corporations say Splenda is safe, they have said the same thing about aspartame, which is now linked to disease and obesity. They also claim that the chlorine atoms in Splenda are altered and therefore safe, yet it’s known that any animal that eats chlorine (especially on a regular basis) is at risk of cancer.
Emphasis mine. Common table salt, in case you forgot, is NaCl/Sodium Chloride; for that matter, the body uses chlorine atoms internally for a number of purposes, including producing stomache acid.
This is not to say that sucralose is safe or not, just that the argument this kook is presenting is, well, silly.