And this is why it's important to pay attention to apostrophes.
Yes, somehow more than one person thought Rob Corddry in clown makeup with bloody scrubs and Ken Marino extending his middle finger were actually intended to promote CHLA. The real hospital is in the midst of a "branding campaign," so you can understand the confusion.
Except no, you can't, because seriously, how could you not get that it's a joke?
Here's the memo CHLA sent out—
It has been brought to our attention that there is some confusion surrounding a series of area billboards and bus stop advertisements promoting the adult television show Childrens Hospital. Please be advised that the advertisements are in no way associated with CHLA.
Again, the apostrophe is key: the titular hospital in Childrens Hospital is named after a man named "Childrens," and that's why it's spelled sans apostrophe. See, it's funny.
But sure, as an advertisement for an actual children's hospital, I can see how the Adult Swim billboards would be troubling.