Every other week an article or discussion surrounding the evils of unpaid internships is addressed in some medium. Here's today's: http://www.cbc.ca/news/politics/story/2013/06/26/f-unpaid-internships-labour-laws.html
Of note, here are the legal guidelines when it comes to the role of an unpaid internship*
• The training is similar to that which is given in a vocational school.
• The training is for the benefit of the intern. You receive some benefit from the training, such as new knowledge or skills.
• The employer derives little, if any, benefit from the activity of the intern while he or she is being trained.
• Your training doesn't take someone else's job.
• Your employer isn't promising you a job at the end of your training.
• You have been told that you will not be paid for your time.
Have there been problems with internships in the past? There will always be people and companies that try to take advantage of the system, but most companies are in it for the right reasons, and most experiences are well worth the time the student dedicates to his or her internship.