NCI / New Citizens Incorporated Tier Donation
And that is what has happened recently. A donor removed 6,000 square meters of tier donation (6,600 square meters which includes the 10% bonus given to tier donated to a group).
Ideally, NCI (and perhaps other groups as well) would prefer to rely upon a larger group of smaller tier donors, so that the loss of one or two donors has a reduced impact.
With that goal in mind, NCI is trying to secure tier donations from Premium Account members who (1) are not using their 512 square meters at all, (2) are perhaps not interested in using their Linden Home anymore and would consider abandoning it, or (3) have a fragment of tier remaining that they could donate.