Websites like TenantDeadbeat.com are protected under federal law by Section 230 of the Communications Decency Act. Your attorneys will find dozens of relevant cases if they are not already familiar with the statute, but Zeran v. AOL, 129 F. 3 327, 330 (4th Cir. 1997) is a well-known example.
Careful consideration should be taken if you are considering legal action against a reviewer. Defamation suits are expensive, difficult to win, and tend to draw additional attention to the issues you would prefer ignored. You will also run a risk of the Anti-SLAPP statute requiring you to pay attorneys’ fees to the other side. Rarely, there may be cases where legal action is appropriate, but in general, it is unlikely you will find what you are looking for by suing someone who gives you a bad review.