Two things...
1/ The folder is in the root directory, nothing here can be trashed. You can write to it, but you can't remove anything in the root directory. The folder has a special flag, what's called the "sticky bit" set.
2/The folder itself is owned by the system and not the user...again, it can't be trashed by the user.
If you need to get rid of it, you'll need to become the super-user and temporarily modify the root directory, as in removing the "sticky" bit, in order to remove that folder.