I have used VideoDownloadHelper for several years now, their team's dedication to keeping updated through numerous firefox versions which keep breaking extensions and plugins deserves respect. I have tried a number of others in the hope of finding a 'perfect' video/audio stream ripper/downloader but keep coming back to this one. It is a pity so many video streaming protection and obfuscation and ad-interleaving mechanisms keep making even this great plugin sometimes find only multi-byte, multi-Kilobyte video headers instead of the multi-megabyte full stream, or sometimes no stream at all, but when it works, it is great, how would we survive without it :)