Mystery weeder - you're NOT helping

This morning, for the second time, I went out to find a pile of weeds had been left on the sidewalk in front of P. Garden. OK, last time that was sort of helpful - although they hadn't been removed by the roots, at least it slowed weed growth. This time though whoever did it also ripped out a lot of California poppies, a clump of Corn Marigolds (Chrysanthemum segetum) and a Ceanothus...

I replanted the last two and thought it must be a kid, as there seems to be a lot of orange candy sprinkled wherever there is damage in the garden...

*sigh* I have to weigh the positives against the negatives. I'd estimate that for every 100+ positive comments, helping hands, mystery plant gifts, donations and so on, I get one instance where someone does something negative - destroys or steals a plant, doesn't pick up dog poop, lets their dog pee on a plant until it dies, tags the wall or gardening equipment etc.

Some of the negatives are easily understood - lots of people don't know that dog pee can kill a plant just like poison. Taggers are just kids with too much time and not enough guidance from their parents. But what about ripping out plants in the middle of the night? Could be a combination of unsupervised kids or mental illness. US jails are some of the biggest mental health facilities in America, so I predict this problem is not going to improve, since people are often punished, not treated, for mental illness...

How do I deal with this? So far I can only come up with one solution: try to care less. This feels at odds with the very idea of creating a community garden, of putting effort into something for everyone to enjoy. If anyone else has suggestions, I'd love to hear them!

However, I don't want to take away from the positives. Last night I came home and found a big Aloe, some little pink succulents and Mexican feather grass clumps - must have been Leah! Then I went out to El Cerrito and picked up a big pile of succulents that craigslister Lloyd left for me. Thanks Lloyd and Leah - I can't wait to get them all planted!