Because Fabric mods run with the same privileges as your Minecraft launcher, a malicious mod can do everything you can do on your PC.

If the mod works at all, it will only work on an unmodded, non-anticheat local server you own – where you could just use creative mode anyway.

: Allows players to duplicate the item currently held in their main hand.

Many duplication glitches involve GUI screens, such as chests, shulker boxes, donkeys, or crafting tables. By interrupting the closing animation or artificially sustaining an open menu via a modded client, players can trick the server into thinking an item exists in two places simultaneously. Chunk Loading and Force Crashes

Tools used by server administrators or mod developers to find, trigger, and patch item duplication glitches to secure economy servers.