This list should be kept hidden. If people know who the sources are they will follow them around the forum begging and harassing these sources.
Just my opinion.
It has and will continue to be easy to identify merit sources just by looking at the volume of merit sent compared to the amount they have received. If you look at the merit statistic pages it's quite obvious who's the merit sources there.
I agree that a list shouldn't be made but it's not going to stop people identifying merit sources and harassing them. But if they are harassing them maybe the merit sources could report this to the moderators if it's breaking the rules?