We need to be able to define Field Level Security based on criteria other than profiles!!! In a public model, there are lots of instances where you want users to see all records, but you only want a subset of them to view specific fields, and that subset is not defined by the users profile. Some Examples: - Everyone can see everyone's opportunities, but you only want the owner and people above him/her in the hierarchy to view the list price and discount fields. Otherwise, these should be hidden. - You want everyone to see every account, but you don't want everyone to see the current amount of business fields. You just want the owner and people above him/her in the hierarchy to view it.