How about one in which someone using your account to post has already swallowed the premise that there are people who can labor, but who are holding out for better pay because they are free to do so. Would that do?
I'm not sure I understand your example. Posting on Free Republic not only isn't labor for me, but you're also supposing for the sake of argument that someone else is using my account.
(Because I have not denied that there are people who are holding out for better pay because they choose to do so; only highlighted actual observations of people who are unwilling to do a job they voluntarily applied for, and who are likewise being notorious slackers about it. It'll be hard to "hold out for better pay" in the eyes of other employers if you were fired or let go from a lower-paying job due to poor performance.)