"A homeless man has been sleeping at Hollin Hill for a little while now. He started building a wall under some problems, which my friend dismantled so she could climb. He left a note saying "How would you like if it i dismanteled your wall". Fairly harmless at first. The wall building and taking down has happened a few times.We have just been this evening and found more sinister things. There are now some air rifle bullets being stored at the crag in a tin in the the wall and a note which says "When I catch you, I will carve my name into your face". We don't know if this is aimed at my friend or is something else but we left pretty sharpish.Landowner, BMC and police notified. "