I see beggars on the street and want to help now and then, but my issue is so many liars are beggars as well. By that I mean there are groups that dress up dirty and go to street corners begging all day, then get picked up and go party all night from the money they begged for. They're not really poor, just lazy.
Well, I don't think of people that way. I am not very religious, but I try to follow as much as possible. In my religion, it is said that when a person comes to you for a need, they should never leave empty-handed. It is also said that, when you leave someone empty-handed, that day can come to you as well. Maybe not today, not to you, but to your future generation. The role could be reversed.
So I try to do all the good I can. Sorry for bringing up religion here but I follow this and I think it is the best. Whether someone is in need or they are just impersonating or faking it, I am giving it to them so that I can feel that I have done something good. And I think I will get something as a reward for that from god.
I will do my part and god will do his part to reward me. If someone is lying, they will also get their punishment from god as well. If I stop helping people just because some dude decides to scam me, then I will not be able to help someone when they are really in need of help.
Sorry for the long reply but that's just how I feel.
And lastly, everything could be used for good or bad depending on people using it. but as you said, people will always be greedy and they will search for their advantage. And they will use it to create conflicts.