What do you need to do in order to mention a product on a TV show without the company suing you?

Like, if a TV show mentioned, say, Coors Light beer, what would they need to do in order to do that without getting in trouble? I'm just curious. Sometimes in TV shows, I see the characters bashing certain products, like saying they're terrible, or a certain product from them was a bad idea. Why would a company pay for someone to bash their product???
Answers

Allison

You would need to have the company's permission in order to mention thier product

Anonymous

Nothing. There are no legal grounds to sue you in this situation.

babyboomer1001

Why would they sue? Companies PAY for the advertising.

Gypsyfish

You've got it backwards. Companies PAY TV shows to mention their products. It's called "product placement"- and it's good advertisement for the product.