Doing a search (which I'm too lazy to do) would yield some dozen or so threads on the matter.
A quick answer is this - symbolic references directly impact the symbol table. This could result in clobbering a variable you already have. As this is completely dependent on run-time activity, debugging this could be complex.
------ We are the carpenters and bricklayers of the Information Age.
Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.