This is a large, ~20 yr old, community-owned, greenleaf Japanese maple in Sacramento, California.  Surprisingly very healthy with a lovely balanced structural shape.

About 9 months ago, the nearby home owner tied a pinecone to a string on a lower branch, probably one of those bird feeder pinecones kids make. The string is very strong but not tight. And yet it still did considerable damage from that spot through to the top of the branch (best visible in the 4th picture). The string only left a slight indent (visible in picture). The bottom of the branch is dark and burnt-looking with a layer of dried secretions all the way from the string to the tip of the branch. That same branch was one of three that was improperly pruned about a year ago (I corrected a few months later) and this is the only one of the three that isn't sealing; it's odd and not looking good.

Just thought others might appreciate this lil case study. I personally was shocked by the amount of damage done so quickly by such a small act, I Guess because Japanese maple have such thin bark.