Has anyone had any success using a nighttime video camera to observe who's doing what inside the garden, to identify who's responsible for what damage?
Josh, I recently purchased a Cisco Wireless-N Internet Home Monitoring Camera. It could be used for your purposes. My use for it is observation of my parrots and maybe to have a live webcam that my friends, also parrot nuts, can observe by invitation.
I think you might find it a good product for your purposes. The literature says you can set up several of them and also have them activate via motion sensing.
These are not infrared cameras, so some light would be needed to illuminate the area if used at night.