I think you forgot a very important element. Its a free market, they can do what they want. In a normal market However they enjoy specific liability protectio

I think you forgot a very important element. Its a free market, they can do what they want. In a normal market However they enjoy specific liability protections (230),unlike most market participants. So, if they exercise choice, they also forego the liability protection. They can choose to editorialize, at a cost of losing regulatory priviledges