Disclaimer: not a lawyer, not giving legal advice. That said, I would agree with greenyoda, although I understand your intent and your point; making that point via recorded phone calls seems to be a bit of a foolish decision. Perhaps write a blog post on your experience, or, preface your interview calls with a notification of the fact you are recording.

Your profile on soundcloud states you're from Miami Beach area and many of the companies you spoke with, or at least a few of them, are based in California. Both Florida and California are two party consent states, opening you up to a large degree of legal liability. That liability includes criminal charges as well as a potential cause of action in civil court (which could be initiated by each company against you individually). Personally, I wouldn't be sure a potential of 26 civil lawsuits and criminal charges are worth the point you're trying to get across here. Similarly, not knowing about the law or not realizing this was illegal, likely won't get you far as a legal defense.

Not to be harsh or negative towards you, everyone's opinion is always welcome here, just be careful on how you achieve/articulate it. I just hope you're aware of the law and I wish you luck.