What crime, federal or otherwise, does he think is being committed by texting him? How does he think the criminal texters will be identified? Once identified, who will arrest them? Who will charge them? Does he not realize that continuing to engage with them hands them a perfectly viable defense, that it's no longer harassment, but a conversation? How long a sentence does he honestly think they'll get, assuming they're convicted?
The answer to all these questions is undoubtedly that he hasn't really thought about it. He's not a smart man, and he's amazingly ignorant. He doesn't have even the faintest glimmer of knowledge about how the criminal justice system works. He has a child's view of things, "You're going to JAIL, FOREVER AND EVER!". It's some sort of reassurance fantasy. He thinks his copypasta is some kind of magic spell.