If you can see it from the street, everyone driving by can too. If everyone within a block or two can smell it, they can also find it without a whole lot of effort too. Or they could just tell their friends that they saw it and word spreads, so It really could be anyone.
Either way there's good reasons to keep things quiet no matter if its legal in your area or not.
I pointed out as much to someone here on RIU and they totally didn't get it:
Oh shhhh you sir are a hillbilly who probably gets with his cousin you know it’s true…I mean you obviously can’t read You're still just about the worst low wattage troll on RIU. But then, my plants haven't been sitting in a dark shed all week.
www.rollitup.org
Also, note that ^ that grower is NY as was my acquaintance who had his plants stolen...it's technically not legal to grow in state yet, so well worth being quiet about it because while most cops probably don't care, if someone holds a grudge and wants to start shit, you're giving them a target.