The hairiest issue here is when there's student participation. But you don't need each quarter to be online, just once every time there are significant course changes. The quarter that will be uploaded could be announced as such and students could consent to being recorded. But this isn't a big deal, MIT has a lot of open courseware with students being recorded. It'd be easy to survey and compare student experiences with/without recordings. But the benefit for the public could be enormous! Think about the public good of every publicly funded university's courseware being accessible online for free.