Question

Hello Rabbi,
There are several websites that provide a ranked database of tradespeople and service providers, where the ranking is based on user reviews. After hiring a professional, the site staff contacts the customer to get his opinion. The question is whether it is permissible to give a negative review (from the standpoint of the laws of defamation / harmful speech). A negative review can harm the professional financially. In addition, sometimes the negative review may be accompanied by feelings of revenge, and perhaps that also violates the prohibition of taking revenge. On the other hand, if no one gives negative reviews, people will not know to be cautious of problematic tradespeople. Another question is: even if we say that it is permissible to give a negative review, the question is how careful and precise one must be in the review so that even a slight exaggeration does not become slander, or perhaps we should say that inaccuracies within reasonable bounds are considered permissible, because otherwise a person could never be precise to the proper degree, and would have to soften the review in the direction of kindness in order to keep a safety margin from harmful inaccuracies—and then again the public would lose out because of this.