Helplessness Argument
When agents (human or machine) make choices at random, they lack free will because the choices are then beyond their control.
The Shaffer Argument
Shaffer asks:
"'What causes the wants and beliefs that constitute reasons?'"
He then cites the following possibility:
"...the wants and beliefs themselves have no causes, arising spontaneously and randomly...But...if...the wants and beliefs arise spontaneously and randomly (which is what it is to say they have no causes), then the agent is at the helpless mercy of these interruptions within him which control his behavior..." (J. Shaffer, 1968, p. 106).
"Since beliefs and wants cause our decisions and actions, it would seem that we do not seem to have control over our decisions and actions. Given our beliefs and wants, we must decide and act in a particular way and can do no other. And how could such decisions and actions be free?" (J. Shaffer, 1968, p. 108).
References
Shaffer, J. A. 1968. Philosophy of Mind. Prentice-Hall