I think it should be possible to find out one's ID that is used for submissions and retain it e.g. in the case of hardware changes or what other reasons my cause it to change (e.g. re-installing windows).
The main idea is, when people re-rip CDs they've already submitted under some ID, it would get counted again if that was submitted under a new ID.
Such submissions would however not add any new confidence, instead they'd rather harm the DB as alleged confidence is built where none is.
This problem is especially grave for all very rare CDs, where confidence values are typically pretty low (I have many CDs where only 1 or two other people made submissions earlier), if these are then however bogus, because it was always the same guy, just with different IDs - that's bad.
Concerns were brought up in the forum, that the possibility to manually set the ID could actually be used to maliciously feed lots of wrong data into the DB.
In principle that's true, though even the current model (basing the ID on some windows internal IDs) is probably nothing that cannot be easily hacked (and if it's just by taking the client, changing the code and submitting random IDs).
So I don't think that this argument really counts.
Still, if people feel the current "security-by-obscurity" like model works in practise, the request of this ticket could still be implemented, by not allowing people to set arbitrary IDs, but rather by generating and ID file (e.g. on the first hardware that a user uses) and allowing him to copy over that file to other nodes.