Curse of Recklessness

Curse of Recklessness, or CoR for short, was a Warlock Curse that caused the target to ignore all fear effects and reduced their armor but increased their attack power.

Talent improvement
Several talents affect all Affliction spells including this curse:

Suppression reduces the target's chance to resist.

Grim Reach increases the range to 33/36 yds.

Contagion increases dispel resistance.

And as of patch 3.0.3, Frailty reduces the amount of attack power granted by your Curse of Recklessness by 50/100%.

Tips and tactics
This spell if useful for any humanoid that might run near death. Look for the "runs away in fear" emote around 20% health. The trick is to place CoR rank 1 (lower mana cost) just before then, leaving a more useful Curse on for the majority of the fight.

In raid encounters you can increase melee DPS by 6-12% for a nominal increase in damage on the main tank. Use this Curse on any boss who does not use abilities modified by Attack Power (ie Mortal Strike or Enrage).

Curse of Recklessness also nullifies Fear. This means that a Warlock can easily CC by casting fear on a mob, and then casting CoR just before it gets out of range. This allows time for a pet to take aggro or your party to finish it off. If the mob gets back to you before the original fear would have run out you can cast another curse, canceling CoR and the mob will start running again.

This curse can also be useful against casters, as their attack power is not used.