LOL...if people read the chemical name for water and were that easily frightened by chemical nomenclature, they'd never drink it!
I've used Splenda since it became available to the public and haven't had a problem with it, nor has any member of my family. Any time you have a product that's been tinkered with chemically, there is a small risk that a portion of the public will react to it in a negative way. For example, there are a host of medications that cause allergic reactions in people, but nobody is screaming for them to be taken off the market because of it simply because the benefit to those that don't have a problem with it is greater than the problem for those that do. If you know that you react badly to something, the solution is simple...don't put it in your body.
Something else that was pointed out in an earlier thread regarding all those letters is note how similar all the writing styles are...suspiciously so. Makes me wonder if they're real letters myself.