route value can be used in URL

Hi,

I've just discovered that the route value can be used in a url e.g. This route

Code:

$route['products/get/all'] = "main/getAllProducts";

can be run with example.com/products/get/all or example.com/main/getAllProducts


Is this by design?
Or, have I done something wrong?
Is there a way I serve a 404 if a user uses the route value?