What you need to do to copy Flash videos from the browser cache (this works for other browsers as well, but you need to change the cache directory) is as follows: Furthermore, you cannot simply keep the page open and then copy the file because these files are opened in exclusive-access mode, so trying to open or copy them gives an access-denied error.
Flash video files are marked with a delete-on-handle-closed flag whereupon as soon as the handle to the file is closed (eg, the page it’s playing in is closed), the file-system immediately deletes the file.
