One of our greatest tests we have, is in knowing who to give to. We often tend to weigh up who we feel is the better person, the better organization. Then, when something comes our way to "prove" that the recipient is no longer a good cause to give to… we give up on them. It's only too easy to have our regular charities that we give to, and then give up on them due to hearing a "true" bad report.
The Chofetz Chaim in a note to his work – chapter 6:11, has this to say:
"And from the law discussed, let us talk about one small particular issue that many people stumble upon. For example, there are people in the city that are known to be poor and one has to give them charity. And now it happens that somebody spreads a bad rumour about them (i.e. speaks malicious evil slander.) They say that actually those poor people asking aren't poor at all, but rather they make themselves out to be poor in order to deceive people. Through their bad rumours they prevent many other people from giving of their regular amounts to these poor people at a later stage – amounts they were accustomed to give them from before hearing the rumours.
According to the Torah, this is a most grave sin because it enters into the category of listening and receiving evil slander. If one would go by the Torah law itself that one may not listen to evil slander – except for the sake of being suspicious about a certain report – one would never exempt oneself from this poor person now, because the poor person would still be established under his original status as being considered a poor person – all the while that one cannot prove with certainty that the opposite is the case – and the people of the city are obligated to sustain him.
Greater than this our Sages have said (Bava Batra 9a) "If someone comes and says 'Support me', we do not investigate after him (i.e. we believe his need for charity.)" All the more so with our case, that this person was already established as being considered poor. Can one do away with the establishment and the obligation of the people of the city to abstain from supporting him any longer – just because of someone who has slandered him?
One may only be suspicious of the report and to investigate into the matter well (to confirm if indeed it is true.) Certainly, all the while that it is not proven true, one cannot exempt oneself from the law of obligation of charity.
About this and similar things, our Sages have said concerning the verse "Do not steal from the poor man, because he is poor" (Proverbs 22:22) refers to a person who is accustomed to giving charity to a certain poor person, and then he stops and he doesn't give him any longer. Such a person is called someone who steals from the poor."
How often have we found ourselves in the position of giving to others regularly? Time may have passed by with a variety of reports coming through from various "authorities" about the true character and financial position of the recipient, proving well that he is simply no longer deserving of the charity one used to give them. If indeed, one finds himself in such a position, and realizes that it is due to the evil slander that one has stopped giving the other, then it may do one well to consider the words of the Chofetz Chaim.
One who actually believes the forbidden malicious evil slander of another to be encouraged to now stop giving another in need, is no better than a thief. Not only does he steal from those that have; he literally steals from the poor (often because he is poor!)
The power of the tongue does certainly bring life and death to others. Next time we have the opportunity to hear the vicious slander told to us about our "friends", we may well consider the strength of the tongue. No knife is a match for the tongue, no sword and no gun. The tongue is far more powerful than all of these. It works far faster, and it brings total destruction in its wake. While those with wealth are affected by the power of the tongue, those lacking the basic means to live can literally give up hope in life itself through the "uprightness" of individuals who simply must tell the "truth."