yeah, the need a federal subpoena to use your IP to start from your ISP, (tracking it otherways isn't admissible, and won't get you a search warrant.) if you get caught, you probably did something to deserve it (like selling, for one, telling all your friends, already a felon for another reason, etc.) frankly if they're already investigating you, and you post a pic of 100+ plants here and they happen to see it (won't happen, they need permission from the site owner to conduct their investigation) they'll be knocking on your door for tax evasion or firearm charges before they can prove you grow anything, just costs them too much time/money to single us all out for it; heck they'd have to go door to door just to find who smokes it, let alone grows it...
just keep your mouths shut and your hands on the keyboard, safer to talk here than in an alley I say.