Trashing is the act of abusing rights to vandalize a player's room. Trashing a room usually involves rearranging furni into a complicated mess (or arranging it into hateful words) and erasing stickies. With the help of the :pickall command however, which picks up every furni in the room, rooms can be fixed.
Group rooms can also be trashed. However, the effects can be more damaging than regular Habbo rooms. With groups, the "trasher" could kick everyone out of the group, delete notes,and stickers. Deleted notes cannot be recovered. Some forms of trashing can also include "blanking" the group (deleting everything, including stickers, notes, and widgets, leaving only the Group Information widget), or filling the entire page with offensive notes. In before, because the effects are more damaging than room trashing, the owner must be extra careful giving admin rights, as giving rights to the wrong person can be devastating to the group.
A common system used is to fill all of the spaces in a room with items that can't have items placed on. This allows people with rights to only be able to activate furni (like opening doors) and rotate some furni. A common way to purchase pet food in bulk and simply place it on rugs so players can still move freely around the room.
There is a way to reset furni to its original state using wired mechanics. However, this can prove to be expensive from the materials and space potentially needed.
Though it won't physically (in-game) help to stop people trashing group pages and rooms, taking a screenshot of your creations can provide a guide to assist you in rebuilding it.