Tested Minecraft Versions:

• 1.8
  
• 1.9
  
• Should probably work in 1.10 let me know if not.
  

ServerProtect is a plugin that enables you to lock and unlock your server to building. Not only can you lock and unlock the server, you can also lock and unlock specific players. This plugin is for creative and survival servers, and is meant for staff use. Here is some information.

Commands:
/lock
Lock can either have a player to lock as a variable, or it can be a standalone command. This will prevent players without the permissions "serverprotect.*", "serverprotect.ignore", "*" or opped players from building.

/unlock
Unlock works the same way as the lock command. Players can either be unlocked, or the server could be unlocked.

/spinfo
Information command, states the plugin name, author, version, locked status, and staffonly status.

/sphelp
Shows all available commands to a user. (will only show them if they have the permission for that command) NOTE: This command will likely be worked on in the future.

/spperms
Shows all the permission nodes in game, and explains what each node does.

/rqul
This command means request unlock. If you or the server is locked and you have the correct permission, you can issue the command to ask any staff member to see if you can be unlocked.

/staffonly
Upon starting your server, the plugin gets the Ping MOTD and puts it in the config file. The reason it does that is because when you issue staffonly it sets the server to staffonly mode and changes the MOTD to "Staffonly mode!". This will kick any online non staff members off the server until it is issued again to disable it.

Permission nodes:
- serverprotect.*
-All serverprotect permissions
- serverprotect.lock
-Ability to lock the server.
- serverprotect.unlock
-Ability to unlock the server.
- serverprotect.lock.player
-Ability to lock a player.
- serverprotect.unlock.player
-Ability to unlock a player.
- serverprotect.info
-Ability to see plugin information.
- serverprotect.help
-Ability for plugin help command.
- serverprotect.ignore
-Ability to not be locked.
- serverprotect.permnodes
-Shows plugin permission nodes.
- serverprotect.requestunlock
-Ability to request unlock.
- serverprotect.receiverequest
-Ability to receive the requests unlocks.
- serverprotect.staffonly.command
-Access to staffonly command.
- serverprotect.staffmember
-Wont be kicked on staffonly command.

Notes:
-- You can disable the request unlock command in config.
-- Opped players cannot be locked!
-- Players who have serverprotect.ignore are kicked from the server when staffonly mode is activated.
-- To use staffonly mode, just issue the command once and it will enable, issue it again to disable it.

If you have any useful features you would like to see in this plugin, comment, or send me a PM!