People work on passion projects and help others for free all the time, but at what point does it become a potential labor liability? Please discuss the following in your post:

1. When may a group of friends dabbling with some code on the weekends require some or all of the participants to be paid a minimum wage under most labor laws?
2. When does a corporation's attempt to provide exposure to real-time industry situations transition from an "unpaid internship" to a pseudo employee or contractor?
3. What are some other examples of people contributing or creating value that often goes uncompensated in the corporate environment?
4. How does not compensating someone potentially affect a company's rights to their intellectual property?