Megaprims.

So Linden Labs is looking at megaprims (prims over 10m on an axis) and what could be done.

Without going into the problems, I'd present my solution:

• Expand the client size limit to 32 m.
• Force any over 16m to be non-physical.
  
• Ban and remove any that are 128 m or over.
• Ban any user that has a 256m or over for breaking the sim and client.

http://blog.secondlife.com/2007/10/12/the-big-prim-problem/