How can I filter inappropriate youtube videos?

I am developing an application that runs completely unattended and displays some info on fixed monitors (like in an hotel hall). I'm planning to allow users to submit videos using a web site, and those videos will be displayed every day at a certain time.

As this program is completely unattended (no moderation desired), it should automatically filter inappropriate videos (sexual, violence, etc)...

So, the questions are:

Is YouTube filter automatic or does it need X users seeing the video and marking it as inappropriate?

How much time does it take to detect that i开发者_运维百科ts inappropriate?

Thanks to anybody that can give me ANY piece of information!

It is dependend on users flagging a video. I really wouldn't do it the way you are proposing, simply because there will be videos slipping through the net you are putting up; and I don't think you want to allow that.