Get scissor cut black plastic sheet, something that’s ridgid, and silicone fishtank adhesive.

Cut the plastic to match the shape of the glass sections that face your window. Clean the glass with alcohol, then apply a thin layer of silicone to the plastic piece and press it to the glass. Use a finger to wipe any excess and ooze into a tight seam.

So long as it doesn’t hit sweltering hot, freezing cold, or rainy for the next 24hrs it takes to cure, that plastic isn’t comming off without a putty knife and effort (it will come off fine without harming it, but not on its own)

If you want to increase the chance that no one will do anything about it, do the same to every lamp on your block. Nothing hides vandalism like uniformity.