We are delivering FLV video to clients using progressive download. If a computer has real player downloader installed anyone can download these videos. How do we pre开发者_运维百科vent this from happening? If we use a streaming media server like FMS, Wowza, FFServer prevent people from downloading videos?

What other methods can be used?

Yes. (But...)

Using a server that streams the content over RTP/RTSP (like Wowza, FMS, et al) prevents the current RealPlayer Downloader from capturing the content. Joost Example

But, at the end of the day, your content is still technically vulnerable. Fact is, if you are sending video content to the user for viewing, then there is a technical means of capturing it. It would not surprise me if RealPlayer started capturing UDP-based streams some day. Or some other tool became popular.