Is my neighbour allowed to rummage through the bins?

I live in a complex of flats made up of two blocks. The neighbour in question lives in the other block to me. He is so nosey. He has a key for our block and comes in rummaging through our bins and commenting on how many wine bottles are in there and he takes stuff out that we've put in there. I threw out set of ugly gles and some old pans which I saw him trotting off with and a big piece of cardboard which he puts on the front of his car. Is he allowed to do this or is he invading our privacy? He is really starting to annoy me now and I feel like locking him in the bin room next time I see him in there