I personally don't see a good rationale for needing to recognize any of them as utilities.

There are alternatives to Amazon, Facebook and Google - good ones at that - while it /could/ be argued that a search engine is an essential product, I would argue the opposite - and even more so for social networking and online shopping - if I saw conclusive proof that any go them were using their market power to force competitors out of the market, I might be more agreeable to the concept.