On a parcel, provide for a list of avatars and individual maximum prim limits for each. Both a manual menu-based interface should be provided as part of the estate tools, and a script interface as well (a must).
The menu interface should have a default prim maximum, which if set to zero, would disable building on that land and set the no-build flag. It would also have a list of agents/avatars that can be edited, with a maximum prim limit for each. This limit can be more or less than the default, and if set to zero, that avatar can not build on the parcel.
The script command [ suggested name: llSetAgentPrimLimit( key agent, integer max_prims ); ] would need to be run from a script in an object over the plot, similar to the land deformation function.
Setting an avatar's prim limit lower than the number of prims they have rezed will return the excess in the usual order.
USES:
Mainland and land rentals -- limit tenants' prim usage as per the terms of the agreement
Event Control -- allow only event participants from building or rezing items
Abuse Cleaning -- allow scripted access to the "return objects owned by ____" interface feature for authorized non-land-owners
EXTRA CREDIT:
integer llGetPrimLimitFor( key agent )
integer llGetPrimUsageFor( key agent )
Use groups as well as agents: Group settings should override the default limit. Settings for individual agents override any group limits for groups they belong to.
VOTE HERE: http://secondlife.com/vote/index.php?get_id=749

