I would recommend prudence in your giving -- use whatever means you have (internet, etc.) to research the organization you're thinking about supporting.
I would also recommend keeping your charity as local and personal as possible. If you know someone in your family or church who is poor, it would be best to help them instead of someone half a world away. We're not meant to know about all the sufferings over the whole world -- it's more than a person can deal with.
Anyhow, if you put food into a starving kid's mouth and a bad man takes it right back out before they can swallow it, it's pretty simple. God judges both actions -- you will get a higher place in heaven, and the bad man goes into hell for eternity.
Matthew