Capo = Cheerleader?

Capo is an Italian word which first and foremost means head as in the anatomical part of your body. Consequently; a director, manager, president, chief, or even the boss of a company can all be called "capo".

From the AO US Soccer supporters' website:

What would a Capo be expected to do?:

Direct the entire crowd into unified support of the team.

A strong capo may sacrifice for the good of the crowd, but can stay motivated, loud, and passionate for 90 + minutes. They can hold the respect of the crowd to lead the section for the whole game and for every game.

However, when talking about the head or leader of a sports team, a (military) squad or a group of workers, caposquadra is the most commonly used word. I suspect it is this expression, more than "capo" itself which has been loaned to the soccer team supporters' group.

Update
After doing a little Italian research, I can confirm that "capo" is indeed the Italian football supporter responsible for co-ordinating the chants, football songs, and cheers of encouragement. He is recognized as the leader of the Ultras (Italian here); "armed" with a loud-hailer the capo is assisted by several colleagues to help sustain the level of support.

Capo is a position in the Mafia - not the Boss or his deputy, but the head of a branch: see Wikipedia's article for Caporegime.

Here is seems to be being used for the head of a section.