I never give my money to beggars, because they do not deserve my money. The only thing they do deserve are my words; to stop begging, and get a job, instead of begging. I also tell him that they got themselves into the situation, so they are the ones that should get themselves out.
Giving money to a bump just encourages them to live their current lifestyle; ask for money, get some, and then get something to eat with that money. Now, if one did not give money at all, the bum (provided that he/she is wise enough) will see that people will not spare him any money, so it is either he dies or he getting his life back.