If a user did that, all those digital files are on his or her machine in mp3 format. They are not lost. And the files you bought from the Apple Store are also on his or her machine, unlocked and without DRM.
Don't get so overwrought. The business people at Apple are not as stupid as you make them out to be.
Yes, the people at Apple ARE that f*****g stupid. They are douchebags. Straight up. And, to reiterate, stupid.
Apple is dead to me.