Your Mastermind Course must not contain content that infringes upon or violates the rights of any third party, including copyright, trademark, privacy, publicity, or other personal or proprietary rights.
If you are using someone else's material you MUST have written permission.
You can not use a testimonial or a "compliment" from someone else as a testimonial without their written permission. The written permission must include your right to use their testimonial in a way that covers your course and/or material. See