And besides, it's true

I saw a review of the new movie Bridge to Terabithia (which, in case you don't know because you never cried over it yourself as a child, is based on a very sad, Newbery Award winning book of the same name). At the very end of the review where there is generally an explantation of why a movie has its particular rating (violence, language, nudity, etc.) it says this:

-- Advisory: This movie contains mild violence, mature themes and false and defamatory claims that "TV kills your brain cells."

I don't even really know what to say about this. Is this somehow legally required? Or is it a weird joke by the reviewer? Have we ever seen a joke in that section of a review?

But it has to be a joke, right?
Let's just stick with that theory.