Privacy is a big issue for us as we are under the ATIPP regulations and any student information has to be protected. We find that the signing of photo,video,audio recording forms are a big barrier to many of our instructors as it takes a lot of time and management. It's not just a one-time sign-off (identifying the purpose and intended use) but also the length of time we will use the video.
We do run some videos (not training ones) on our main public web site. These are mostly promotional.
We do have one instructor who operates a great Youtube site where he posts interviews with students and talks about how to succeed when you move from a small community to the "big" city. So far he has had nothing but praise; if someone changes their minds afterwards he just takes down the video. Of course, if you read the Youtube terms and conditions, that video is still on their servers somewhere but it hasn't been a problem yet.
We are exploring the possibility of publishing some of the class recordings to iTunes as the account is free and you can keep your videos behind a password. The advantage for us is that the format is commonly available (to anyone who can download Quicktime) AND it will play your video on mobile devices.
Most of our videos for learning are behind password on our learning management system or in-house blogging platform.