Disable Spawning Blocks

[LochOLand]

Recently on my tekkit server some players have been abusing the ability to spawn in blocks. The simple way to fix this is of course, to de-op them, but this won't allow them to alter blocks at all! I would like to either disable /give, or enable de-oped players to alter blocks. Please help! I am on a Mac OSX.

[warpspeed10]

Have you tried editing your server's permissions file?

[LochOLand]

No, it worked thanks.