[fatdog789]

Free is not, and never has been, a defense to antitrust. Indeed, free offerings are generally considered very good evidence of antitrust: the company at issue is abusing its market power in one market to increase its market power in another market in non-competitive ways (i.e., by using money earned from a separate market to undermine the target market through under-priced goods). The obvious worry is that the products will stop being free (or so cheap) once the company has achieved sufficient market control.

It does not matter what the end user can do, antitrust focuses on what the alleged monopolist is doing.

Also, choice is not a defense to antitrust under the Sherman Act. That's a common misconception among non-lawyers. Choice is only weak evidence, at best, that the an alleged monopolist's activities are not anti-competitive.