Idea Anti Spawner Change

Hello everyone. So since Survival has been down, I have spent a very brief time on Mineage factions. This server was by far the worst server I have ever been on, so don't go freak out thinking I'm advertising. The reason why I bring Mineage up is because they had a very interesting plugin that would improve survival; one that doesn't allow players to change mob spawners via mob eggs. Although having unlimited gold and wither heads are rather nice at times, it doesn't make the server like vanilla minecraft. I have tried to find this plugin, or similar ones on bukkit, but I have failed to find one that was like Mineage's. I contacted the admins and coders on Mineage to see if they would give me information on it but I was greatly disappointed to find that they wouldn't expose their secrets. I'm sure some players will enjoy having a stable economy and pvp without 10 gaps per player. I'm not sure if it is possible to restore the already changed spawners, but at least a plugin like this will end the changes.

The plugin had a message come up in the chat saying "You do not have the permissions to change mob spawners." when you tried to click on a spawner with a mob egg.