My seminary has been releasing public warnings of a con artist on campus. This is a guy who's been around before. Basically, what the guy does is engage students in conversation about matters of faith. He then suggests that they prove their faith through acts of trust, such as getting the person to go to a bank and withdraw money. If the student resists, the guy gets "very manipulative and can become intimidating."
I've had a run-in with someone like this a few years ago (probably not the same guy, since the report says that he tends to target international students), and although I'm cynical enough to stand my ground, and not give in to this kind of manipulation, I always walk away from such an encounter feeling very conflicted. Like I've somehow failed to trust God, despite the fact that the con artist's own manipulative nature is evidence against the situation being worthy of such trust.
I don't have an easy answer to that problem. On one hand, I think that Christians need to be more sacrificial in their giving to those in need. On the other hand, we need to be wise about how we use the resources God has given us, and I'm convinced that this doesn't mean we have to give our money to every potential thief that asks for it. I'd like to encourage my friends who may find themselves in this situation to be strong, and not give in to unwarranted guilt, while continuing to pray that God will encourage us to be more giving to those who actually need the help.