I agree with Steve
. This is completely intentional.
It's you, who is not allowed to know salary of your coworker or friend. Because if you knew it, you'd want to get a better deal from your employer (or even change one). It's them, employers, who want to keep it in secret from you, employee.
Now, doesn't it become logical and explain, why credit report agencies collect and share that info between companies (employees)? They work in their behalf, not yours... And doesn't that explain why they don't want you to share that info?--
Keep it simple, it'll become complex by itself...