Well, stuff like John Doe warrants to look at ISP's customer's bandwidth usage for one. Then a warrant to you to make available your computer for their detailed inspection. Probable cause for the warrant is the assumption that bandwidth useage equals music theft.
Your bandwidth useage (the amount, I mean) is none of their business. What happens is that you, the accused, must prove your innocence. IOW, bare your private information to demonstrate that you are not taking music. You are given the option of doing that via thousands of dollars of legal fees, or paying a "negotiated settlement" which is less than the cost of defending yourself.
Now, if you have not been pirating music, it is still cheaper to pay them off than defend your self. They know this. It is a policy of intimidation and extortion.
An imperfect, but adequate, analogy might be the purchase of large amounts of printing paper at Staples. The book publisher goes to Staples and demands records of customers that buy large quantities. Then comes to you and demands that *you prove* you are not making copies of novels they publish.
The RIAA's copyright rights do not (at least should not) infringe on your Constitutional protection of presumption of innocence.
Keep music files on a usb drive.....