A monopoly is defined as a seller with no competitors (in their market). Facebook would be a monopoly if its user were _forced_ to log in to facebook, use its software, or give it money.

Ergo facebook is not a monopoly.

It's ironic that I would have to define monopoly here - I personally have a great deal of distaste for facebook's actions. In my opinion they engage in highly deceptive business practices. Their users are unaware of the damage to their privacy stemming from facebook's actions.

But unethical or distasteful practices do not imply a monopoly. Google does not have a monopoly either - if you prefer not to use their services, use Bing or Baidu or DuckDuckGo ...

I understand that facebook and google embed javascript on other pages. So download the requestpolicy firefox addon. Or disable javascript. And cookies. I think you can see my point: you, the customer, can spend your money and your bandwidth (= money) other places if you prefer.