I would not characterize this story as speech but as carefully designed viral marketing content. If one is in the business of attracting people speaking with each other and selling that access to companies and political parties then dealing with viral content intended to undermine your sales is a continuous struggle. This one was deemed over the line and a case of potentially Russian disinformation laundering.

When looking at the legalities keep in mind that these companies have been explicitly warned by the F.B.I. of such possibilities and have spent time combing through their own databases and have identified such events.