Creating the reblog function required some careful decision-making regarding the editability of the original blog text. The problem with allowing the reblogger to edit the original text is that this gives the reblogger the ability to insert false text and images. I don't expect this to be a regular occurrence on my site, but I don't want that to ever be possible. Another potential problem is the original blog could be edited after it is reblogged. This creates similar problems. For example, a reblog could be made stating agreement with the original blog, and the original text could be modified to something that the reblogger doesn't agree with.
The solution that I developed involves saving a full copy of the original blog that neither the original author nor the reblogger can edit. The only disadvantage is the extra storage space that I need to do this, but I think it's a necessary cost that I must accept to make this function work nicely.