Is it normal homework to be behind a paywall online?

My friend just started college and in one of her classes the homework is only available online but there's a paywall to get to it. They've already paid tuition to their college. Is this normal? It sounds shady as fuck to me. I feel like the professor is doing something illegal here to be charging students to do their own homework.

If this is illegal/wrong, who would she need to talk to to fix this?

If it makes a difference, the college is somewhere in upstate New York. I don't know which college it is specifically. I can ask if it helps though.