The toys are cool, but there are serious laws against creating boobytraps, so if the law gets tangled up in them, they'll be far more motivated to find your ass and stick you in jail for a good long time. This plays into the hands of enemies as well- the cops won't care if the person complaining about such traps was sticking their nose in places it didn't belong, they'll use it as an excuse to get rough.
I think that ultimately the best way to go, short of an all-out combat situation (and let's face it, this is guerilla GARDENING, not guerilla warfare!) is good surveillance and intruder alarm style stuff. Keeping it simple., like using little ladyfinger style firecrackers on thread across trails, the ones that don't need an ignition source, just to be pulled, would do fine to alert you that someone unwelcome is nearby, and it won't get you 20 years for attempted murder.
If you have thugs coming to your home grow to rob you, then the bottom line is you've already lost your garden- it's just a matter of whether the thugs or the law gets it. How many extra charges do you want?
Your best bet for deterrence is to cause a ruckus OUTSIDE, preferably in your yard or the street in front of oyur place, so the thugs get noticed and leave before the law shows up and ruins their plans. To do this, cameras on motion sensors is key, as are lights and noise. If you can draw attention to them before they get in your house, you stand a much better chance of saving your crops, your ass- and your privacy.