It seems the website info is a little outdated, I've found numerous abandoned areas with locked chests within them. The instructions on how to open chests like these was to claim the area for your faction, however this wasn't the case. As in doing so changed nothing other than having a random chunk under my name. I would like to think that's it's power related, but these are abandoned chunks, no faction claiming them. Honestly me and my friends are the only active users. So maybe it's a bug or an error, but it's quite annoying to clear out an area only to find invincible chests in the way.