There are hosts with multiple users on them, who have some level of write access to somewhere on the filesystem. After all, Unix is a multi-user system, so it

There are hosts with multiple users on them, who have some level of write access to somewhere on the filesystem. After all, Unix is a multi-user system, so it is not heard of to have multiple users on it. That being said, this article is just stating to be careful of wildcards when you are sitting in a user-owned (or user-writable, such as /tmp) directory.