So it's not really *him* attacking those companies. It'd be more accurate to say that the people who voted him in are using him to retaliate against those companies, like a loose union
No, he was directly attacking them on Twitter himself. He was saying he wants to regulate Google search results, as an example.
Right, on behalf of the people who voted for him, exactly. If the search results aren't unbiased then google should be reporting campaign contributions.