Forgetting you are correct and 100 ml = 3.4 oz, the insanity is this announcement is played airside AFTER security. Everyone hearing it has passed thru a Checkpoint and, assuming TSA does their usual super job , No One hearing the announcement is in violation! If the intention is "training the sheeple" for future flights, those that had nothing confiscated at the checkpoint already know the rules, those that just had their 4 oz. of explosive toothpaste confiscated just learned the rules, so everyone will be compliant on their next trip anyway.

That announcement needs to be made BEFORE the checkpoint ONLY. Perhaps they will add a new category on their Weekly Body Count tally next to Unnecessary Terminal Dumps: Millions of Times Passengers Were Subjected to an Unnecessary Redundant Safety Announcement This Week.

I know, it's TSA, better to hit myself on the head with a hammer as a far more productive use of my time than trying to have them develop common sense.