[fragmede]

They can't tell if your copy is legal or not, but if your copy of an album hashes to the same as the copy found via TPB, they'd consider it suspect.

I think there's enough variation in CD ripping software and various encoder profiles that different rips of the same album using different software is not bit-for-bit the same. That would also be trivially defeatable, so I'm not sure what it'd get Google to do that.