Can It Be?

I was just in a 7-Eleven and a big, surprisingly insistent sign near the soft drinks read "Do not take cans out of the boxes! We no longer sell single cans!"

I don't get it. What's wrong with selling single cans? They're cheaper than bottles and plenty of people prefer the size.

Was this a decision made by Coke et al, or 7-Eleven? I thought this was a convenience store.