In which FHS directory would Gavin likely find mount points for unauthorized removable storage devices?

In the Filesystem Hierarchy Standard (FHS), the directory designated for mount points for removable media, such as USB drives or CDs, is generally found under the /media directory. The /media directory is intended for mounting filesystems that are removable or temporary in nature, making it the ideal location for unauthorized removable storage devices as well.

While the /mnt directory is also used for mounting file systems, it is typically reserved for temporary mounts that system administrators might use during maintenance or other tasks. It's not specifically designated for removable media like /media, which is more user-facing.

The /dev directory is fundamentally different, as it contains device files representing hardware devices on the system, rather than mount points for removable media. Lastly, the /var directory is used for variable data files like logs and spool files and does not serve as a location for mounting storage devices.

Thus, for finding mount points specifically associated with removable storage, /media is the correct and logical choice.