The U.S. DoL utilizes the below listed criteria, as created by the U.S.S.C.
(Walling v. Portland Terminal Co. (1947) 330 U.S. 148), to determine whether
a person is really an intern, or whether they are an employee who must be
paid and treated according to the Fair Labor Standards Act (FLSA):
1.. The training is similar to that which would be given in a vocational
school;
2.. The training is for the benefit of the trainee;
3.. The trainees do not displace regular employees, and work under close
observation;
4.. The employer that provides the training derives no immediate advantage
from the activities of the trainees and on occasion the employer's
operations may actually be impeded.
Text
http://www.twc.state.tx.us/news/efte/advanced_flsa_issues.html#interns_trainees
Long story short interns are not a source of free/low pay labor so proceed
carefully as the wage and hour folk have no sense of humor and often link
the information to the IRS which includes an element of personal liability.
http://www.internjustice.com
The exposure does not evaporate when the intern moves on.