I don't know if the system needs to be monitored but it'd sure create a whole new workload for the moderators.
You could have the system where it's allowed to de-rep (at a certain member level that is, to avoid the idiots abusing it) and having a valid reason for de-repping someone. If there were none, then it's abuse either way and should be filed under disputes (unless it has a report button next to the de-rep)
But hey, I'm pretty much still considered one of these so called newphags so, my opinion is probably not that great.