This question, 'Is there an easy way to limit user bandwidth usage?' was closed as a duplicate. The possible duplicate, 'How I can limit Download/Upload bandwidth?' does not answer the new question, only addressing per-OS, per-network interface, and per-application rate limiting. Nothing there about per-user, which I think is an interesting question.
Can it be re-opened, or at least merged into the dupe (and the additional component about per-user limiting addressed)?