I only have one crop, but it is VERY susceptible to the human gnome pillaging, and that is my figs. It irks me to no end that every year people will trespass onto my yard and pick at will, then get offended when I come out and tell them it's private property and they are stealing! I have even had total strangers drive by and stop to tell how much they have been enjoying my figs!
And yes, signs are posted. Last year they even walked over my iris bed to pick figs.