Hmm, my two cents.. Zirocs idea is just wonderful, but if you are afraid to press charges, how would they rect if they use that gas for the car??
Well first of all, get a lock to your shed, a friendly alarm, the fuse to a landmine worls like a charm, used that against apple thieves a couple of years back... Goes with a boom in a secure area but that boom and a tripwire scares people like hell
Get a lamp with a sensor, that way everybody can see them wandering up your yard. That way people will see what is going on and well.. Vitnesses is good to have should this thing go further..
Talk to the mom, if she is like the quennmother of arden thieves i would suggest that you take this up with local authorities and talk about what can be done and so on.. If nothing works.. well try get some rocketfuel or fuel for dragsters... That can be at least as fun as suger and water....
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Yawning lazywolf heading for the cliffs...