Not the same thing (Score 1)

These aren't volunteers -- they're AOL employees.

AOL set work hours, conducted training, and defined the methods by which the "volunteers" were to do their jobs (including internal company paperwork). The observers were given payment in the form of valuable AOL accounts.

In other words, this is something that would set off alarms in the minds of most lawyers (of which profession I am most assuredly not a member), as well as the IRS and FTC. AOL observers are a very different beast than /. contributors, MiningCo guides, Linux developers, Habitat for Humanity homebuilders, and the like. In fact, as far as I can tell, they seem more like front-line tech support than "community leaders."

The argument that all employers and employees have the right to freely contract regardless of the terms -- so-called "Lochnerian free-contract theory" -- has been largely discredited since that Supreme Court decision. When an employer takes on an employee, he assumes certain duties (payroll taxes, minimum wages, family and sick leave, liabilities for negligence, etc.) that cannot be waived by an instrument between employee and employer. By setting minimum standards, employers are prevented from exploiting workers by way of coercive contracts.

I do agree that AOL observers are in an ethical sense hardly the same thing as migrant farm workers or even Microsoft temps. In fact, I don't believe that AOL acted to knowingly deny benefits to employees. Nonetheless, if AOL availed itself of the services of part-time employees, it cannot simply ask them to waive their rights under employment laws.