Is Facebook a Monopoly?

I think that there we definitely need tat no question, need more regulations, more regulatory scrutiny a facebook. What are the costs of having one unaccountable person who cannot be fired, own three of the largest platforms in the world? I don't know what the right answer is, and it is much more complicated than just break it up. The digutal ad thing is interesting because, no, you can't hold Facebook accountable for what all their users say,. any more than you coud hold the phone company accountable for what their users say.