Take one quick look at the side of a bottle of soy sauce and you will probably be shocked at how much sodium it has. Then think about how much you end up putting on your food over the course of an average Chinese meal and you will realize that soy sauce is pretty bad for you.
I love Chinese food and I like using soy sauce in other foods so I always make sure and buy low sodium soy sauce. Everything has so much salt these days. If you don't consciously try and avoid it you will be far above the daily recommended dose without even trying.