Sure, and doing so commercially and without attribution, especially when the code is not CC licensed, can be problematic. SO code is implicitly CC (and furtherm

Sure, and doing so commercially and without attribution, especially when the code is not CC licensed, can be problematic. SO code is implicitly CC (and furthermore, contributed under the expectation that it will be used by anyone) so it’s not problematic to copy-pasta that code IMO. But copying blocks of code from a GPL-3 project would be, for example. To be clear I don’t think learning from (but not cloning) a GPL project is problematic. That is just what normal students do.