Copyright and math teaching

Lately I have been intrigued with the subject of copyright and math teaching.

I have done some reading and concluded that the copyright law is intentionally vague to provide users with flexibility, and that there are two schools of thought on permissible use of copyrighted materials in teaching.

The first school of thought is to take a very conservative approach and not do anything that could potentially trigger a lawsuit. This school of thought adopts the Section 107 Fair Use statute literally, and adopts the so-called Guidelines as rules to follow. This school would say that Section 107 does not apply to for-profit schools, period. It would also say under the Guidelines that you had better obey the brevity, spontaneity and cumulative effect guidelines.

The second school of thought is to take a more liberal approach, and that Section 107 requires an individual assessment of all four factors. For example, if a copyrighted work has no economic value, then the owner is not going to lose money if I use the work in a for-profit school. As another example, if I show before and after steroid use photos of a famous ballplayer in the context of measuring the probability of his post-steroids results, then this is a transformative use of these copyrighted photos from their original purpose, which is permissible.

I'd love some comments to help me think through this.