I have answered to four Scheme-related code review requests on the site, which are for proposed solutions to exercises from a famous text book Structure and Interpretation of Computer Programs (usually abbreviated SICP) which has been used at MIT for a long time in undergraduate education. I have also taught this book in my own university in the past.
Is it appropriate for users to post solutions to exercises from well-known textbooks on Code Review, and for other users to help to improve them? I wonder if this is good citizenship as it makes the life of professors harder as this opens a new, easily accessible medium for getting canned, high-quality solutions from a centralized source.
Should Code Review ban solutions to text book exercises from being submitted?