Dunno about TN, but in NC, a Weapon of Mass Destruction is a legal term referring to anything designed to harm more than one person simultaneously.
This led, for example, to a local headline about a man holding up a bank with a WMD because he used a sawn-off shotgun.
You beat me to it, because I was looking for evidence to support the dick pics thing. I can't find any source I would be comfortable vouching for. Just a grain of salt there.