Originally Posted by $5 submissions

Even if you post it as an OPINION but the intent is to make them lose business, they can hit you with

1) libel (because it's published in digital form) OR
2) tortious interference with contract if they can prove that people were going to signup as affiliates or already had affiliate agreements and broke it off cuz of your post.

Regardless, truth is a defense but you must be able to PROVE it in court. ie., the court would agree that based on the evidence, it is legally true.

DISCLAIMER: This is not meant as legal advice. Consult an attorney in your jurisdiction.