New massive fungus found in China

I've just seen this article on the BBC website; http://www.bbc.co.uk/nature/14294283 .
The fungus Fomitiporia ellipsoidea is, apparently the largest fungus yet found anywhere in the world.  It is growing on the underside of a fallen tree trunk and weighs half a tonne!
These types of wood-eating fungi are usually found on dead wood rather than on live wood.  They break down the dead wood into its constituent chemical parts.  They don't usually pose a safety risk to the tree or to people and property as long as the tree is alive and there is enough new wood to keep it healthy and stable.  Obviously, if the whole tree is dead this could cause safety problems.
The main problems for safety of people and property is when an aggressive fungus attacks the living tissues in a tree.  If this happens the stability of the tree can quite easily be affected.