The Hole-in-the-Wall Gang is a joking reference to any bum that hangs around a cash machine, ATM, or 'hole-in-the-wall'.

The name comes from the infamous Hole-in-the-Wall Gang that operated out of Johnson County, Wyoming during the late 19th century.

Why these beggars ask for spare change by a machine that'll only provide notes of £10 or more, is generally not understood.