There is a third issue, which we saw in spades on the
Phase II
software: once someone is logged in, we will no longer see that
person's IP and therefore will have no way to block that
person--and there will most certainly be people who log in
solely to upload files that should not be uploaded, and who
will deserve to be blocked.
The new software is capable of blocking by IP or by login name.
There just aren't yet any features in the software to add to the
block list by name, or to discover the IP of a logged in user.
Those will need to be added at some point; I'll add that to the
tracker at high priority.