Spawner Glitch!

I was playing Minecraft with my friend on a server that had the spawner plugin where u could break it and craft it. It also had own blocks protection and super pickaxe.

So my friend had a spider spawner that he had owned with own blocks. I tried to destroy it with super pickaxe and it chicked out the items that it ussually droped but kept reappearing where it was placed with own blocks. so we are now able t get an infinite amount of spider eggs and an infinite amount of iron bars!

I dont know if this glitch works on another server under these circumstances but be sure to try it if you get the chance!

The owner or admins havent found out yet :D