Either a big ass, or truly desperate.
If you were a bell ringer, and some destitute looking dude came up asking for help, what would you do — does the Salvation Army provide them with cards directing inquirers to their public assistance offices? Not that there’s any excuse for robbing, but still the question suggests itself.
You don't give them money. You can't anyways, because the kettle is locked, but you don't give them money. Crackheads are notorious for coming up with convincing stories of woe.