Break the terms of service, get mad and write a blog post. It's not even hidden in some legalese; they tell you not to serve majority image/video content _everywhere_ in the UI. All my tunnels are still running great, for free. I could not be happier.
I am not saying I am right. I did break the TOS. They have the right to do what they did. It's just not nice and I don't like them anymore :)
I sure hope your customers read this comment, they should know that you're likely to defraud them, since it's not "nice" of them to want you do what you agree to.