Does Southwest have any rule - whether realistically enforced or not - against hidden city ticketing?

On legacies, I've only done this rarely and with carriers on which I didn't have much to lose (e.g., not a carrier where I held a high mileage balance or status) and never gave them my FF number on hidden city trips. Nothing ever happened to me but there was always this underlying warning that miles could be frozen, future tickets canceled, etc.

Do those of you who do this on Southwest take similar precautions? I consider WN a "near primary" carrier since I'm flying a ton of their short nonstops these days...hidden-city would save me a few bucks here and there but I don't want to wind up on some double-secret "naughty list" by doing it.