You show the command to the user anyway, you just don't show the variable names. Let's say that you are worried that the user will change id.
From: index.php?id=10
To: index.php?id=11
With the other way of doing it they just need to do like this.
From: index.php/10
To: index.php/11
I suggest that you don't worry about this if you are only worried about the user changing the values.