How does music get leaked? : A Brief History of the Bootleg
Music has always been bootlegged but the advance of technology has enabled music to get leaked more easily.
The Mob: The Mob used to hijack trucks full of copies on the way to the retailer. The bootleg records would either get sold on the black market or sold back to the label
The Pressing Plant: Some warehouses are full of records. Some would mysteriously go missing and still do.
Promo Copies: By far the most likely source of a leak. These get sent to journalists, dj’s, websites et al by the label, weeks (and even months) before the release date.
Hacking Computers: Computers prone to spyware, weak passwords or intrusive bluetooth devices that can hack into computers.
Employees: Some engineers & producers sell leaked files to bootleggers and websites. Artists might even leak their own records out of frustration, as Amerie and Rich Harrison did with 1 Thing.
Record Labels: May choose to leak the record themselves to test the market or to drive down sales of a record, in order to offer the artist a lesser contract during re-negotiation. The label will send a Cease & Desist to take the record down under the DMCA.