Online review sites like Yelp provide consumers a voice when it comes to the businesses they patronize. While this can be a plus when a business receives glowing reviews, problems may arise when a customer leaves a negative review about a business. Some business owners even wonder if they can sue the person responsible for leaving the bad review. CNBC.com explains when customers can be sued for the reviews they leave, as well as what they’re permitted to say when leaving a review.

Reputation is a real concern for virtually all businesses. When a person makes claims about your company online, it’s likely to gain the attention of many other people. This is especially true when a claim goes viral and is shared via social media. When the damaging claim a person makes is actually not factual, a business is entitled to file a defamation lawsuit.

Defamation is characterized as making untrue statements about a person or business. An opinion cannot be defamation since it’s nor a statement of fact. Even insults may be protected legally since they’re ultimately just a person’s opinion. However, any claims about an incident that occurred or practices by the business must be based in truth. For instance, if a customer claims she was subjected to ill-treatment by staff and witness testimony suggests otherwise, that person could be the subject of a defamation suit if the business can prove losses occurred due to the untrue negative review.

On the other hand, regulations are in place that prevent a business from suing a consumer for making claims that are true. The Consumer Review Fairness Act stops businesses from citing non-disparagement clauses to intimidate consumers into removing negative reviews or even bringing legal action against them. Non-disparagement clauses are only valid when they’re able to be negotiated by all parties.