1) The 20-year-old guy who makes good use of it by communicating with his team
2) The moron who likes to scream at people on his team, usually resulting in garbled screeching
3) The 10-year-old who barks orders at his teammates when he's losing and shouts "Yipee" when he's winning, only to sound ridiculous either way
Ach, yew kin take oor freedom, but yew kin never take oor Scotch! Ne'er troi to take th' alkohool o' a Mic!