What happens if I write an article about how shit McDonalds is, like really bad and post information about the mistreatment of animals, or the horrible practice

What happens if I write an article about how shit McDonalds is, like really bad and post information about the mistreatment of animals, or the horrible practices that they follow and in this article I link to them. I mean I'm writing this article so that people stay away from McDonalds because I feel its damaging to their health. Would a link to there website on that article be illegal? p.s. Just an example, I love Mcdonalds.