Wasted Cache is a quest given by Mr. Mackey in the Community Center. He requires you to take a computer monitor to his U-Stor-It locker.
Walkthrough
Go to Mr. Mackey's U-Stor It locker and put the computer monitor in there. There is sometimes Nazi Zombies (They randomly spawn there) in the entrance of the U-Stor It, so you may have to fight, otherwise it's a very simple delivery.
Return to Mr. Mackey for your reward.
Reward
Mr. Mackey friends you on Facebook.