I decided a quick post on a pet peeve was in order. Most server/telecomm racks and rack-mount equipment will support cable management, but in many cases the time and effort hasn't been taken to perform this necessary part of an installation. Usually when new racks and equipment are installed an initial effort is made, but as the pace of installation for additional hardware or density of said hardware increases, this task is forgotten as the image from one of my old data centers can attest.
While this mess may not interfere with normal equipment operation, the first time you try to move or find something in a rack, you may be in trouble. Also, a messy rack can impede airflow and your ability to keep the equipment cool, which is a big deal. If cables aren't routed properly, you may not even be able to close the rack doors which could be a security risk and again impact proper airflow/cooling. This article from L-com was pretty good at describing the importance of airflow.
