A living in a cardboard box in an alley way bum? Nothing, as I've never encountered one.
Drug addicts lying and telling me their kids are starving? Countless times, probably a few hundred bucks all together.
Also, "friends" probably well into the thousands, mostly one particular friend though. You said beggar, so I'm still counting this. I had this friend named Tony, well, when I was still a teenager I decided to stop drinking so much(this didn't stick) so all my money from being a janitor I saved, it was only a a few thousand bucks but I made the mistake of whipping it out in front of Tony when we were going out to a party.
After that, every time he needed something I was the go to guy, it started out as a twenty here, then progressed to his distant family members asking me to get their electric turned back on etc..it wasn't just me either, he was doing the same thing to a mutual friend of ours I later found out, ask me for a twenty than go ask him for a twenty as well, with the same exact bullshit story.
I got the fat fucker back though after I ripped him off by not paying him for the difference of a trade of a vehicle, and our mutual friend ended up assaulting him in the parking lot of a dollar general, so I guess it all worked out in the end.