A standard computer keyboard has 101 keys. Of these 101 keys, no key is more hated than the CAPS LOCK key. It’s relatively large size and position on the keyboard cause it to be frequently pressed accidentally. As a good touch typist thinks ahead of their hands, this mistake may not be corrected until a few words have been typed. If the user is typing in a secure text field, this mistake may not be corrected at all. This is especially undesirable when the user is creating an account, as the erroneous password will be used as the credentials for the website. When the user tries to login, they will be denied access despite having entered the ‘correct’ password. As they are new to the site, they will be much more likely to blame the website and leave than attempt to type their password again. Web developers find this infuriating as they are losing customers to a bug they have no control over.
Why was the CAPS LOCK key added to the keyboard if it so useless? The standard OWERTY keyboard was a direct copy of the standard typewriter. When capital letters were implemented on typewriters, the shift key was added to give each key two purposes. It accomplished this by tilting the entire paper apparatus so that the pads attached to each key contacted the paper farther back. Pressing the shift key required significant effort, making it difficult to keep the button pressed while typing. A shift lock key was introduced that held the paper reel in the shifted position, causing all of the keys to print their shifted value. When the first computer keyboards were developed, the shift lock key was modified to only capitalize letters, leaving the rest of the keys unmodified. As the force required to actuate the shift key on a modern keyboard is minimal, the CAPS LOCK key is a solution to a problem that no longer exists.
The main reason the CAPS LOCK still exists is that the market heavily resists changes to standards. Still, a few people are trying to change this. Google replaced the key on their Chromebook with a search key, and the XO Laptop project replaced it with another control key. Some operating systems allow the CAPS LOCK key to be disabled through software. The key can also be disabled through modifications done to the keyboard itself.
I use a Ducky 1087 mechanical keyboard with N-key rollover. N-Key rollover indicates that the keyboard can detect every key on the keyboard individually. Most keyboards are not NKRO as they arrange they keys in grids to reduce cost. This can cause the keyboard to ignore some of the key presses if multiple keys are pressed at once. As the 1087 is NKRO, it can be inferred that each switch is independent of the others, allowing them to be modified without affecting the rest of the keyboard. The keyboard is easily disassembled with a screwdriver to reveal the circuit board underneath.
To disable the CAPS LOCK key one of the switch terminals was desoldered. As the switch is mounted to both the PCB and a metal frame it remains mechanically stable yet is unable to make an electrical connection. As the keycap is held by the switch, this allows the keyboard to retain it’s original look. After completing the mod the keyboard remains fully functional.
charliehorse55 
You can turn off caps lock on a Mac with System Prefs ==> Keyboard ==> Modifier Keys. Nothing like the permanent, OS independent fix, though!