Short answer: You are not anonymous on the internet. Its quite easy to track someone down.
My whole thing, do you really think the DEA/cops/whatever is spending all that time/energy and money to bust your small 4 plant personal grow operation? They could give a rats ass about that. In order to bust you with a indoor setup, they will need a search warrant. They need proof that you are growing (not a neighbor calling and making a complaint, etc... REAL HARD PROOF) in order to get a search warrant.
If for whatever reason you get busted... If you havent been in trouble with the law, its like 1 year probation and paying fines if you get caught (most likely even less if ya get a good lawyer).
I really dont think the DEA/FEDS/COPS are going after personal grow operations, they are looking for the big guys selling pounds and pounds of the stuff.
Best advice is to keep your grow on the down low, and dont sell it. Grow for personal use only.
Cheers,
-bwbig