Rule number 1 - DO NOT TELL ANYONE!
Rule number 2 - DO NOT TELL ANYONE!
If rule number 2 fails, see rule number 1.
Get a Rottweiler.
Smell will be your biggest hurdle, start buying plug in electric scent oil burners/deodorizers/room aroma enhancers (or whatever they are called) and place them all around your yard and out of the weather.
No point filming your ripperofferers, preventing anyone from discovering them in the first place is much better,- weed smell will be your enemy.
Plant plenty of smelly plants in your front yard, like marigolds, basil, lavender or plumerias, especially the last two if in flower. Don't plant basil too close to your plants though, somehow your buds can end up tasting like basil, and yes, I am talking from experience!
I wish you the best of luck in preventing your plants from sprouting two legs and running away!
Just remember rule number 1!
If you have already told people, be very vague about their maturity, make sure to always say "they are ok, but not ready for a few weeks yet" and never, never ever show them to anyone or boast about how great they are looking/growing. I have even heard about an incident where people will even come and dig them out and take them away if they think it will be easier to steal them before the plants flower!
More cameras, even fake ones out the front can help, but can also have the opposite effect, whereby people think there is something very worth stealing due to all the cameras. If all else fails, a pump action 12 gauge shotgun is always a good deterrent.
Cheers, Organoman.