A few points you might want to consider: * youtube-dl is not just for Youtube (ie. google). It supports heaps of sites, and youtube is probably less likely to

A few points you might want to consider: * youtube-dl is not just for Youtube (ie. google). It supports heaps of sites, and youtube is probably less likely to have the sort of content I'm referring to than twitter, pornhub, liveleak, who knows. * I am in Australia, so for a subpoena (or similar) my friends would need to issue an MLAT request, which would indeed take a very long time. In fact, this often does happen, but in the meantime a formal preservation request (to the service provider) and a local copy (via something like youtube-dl) are important steps. * Many investigations don't go to court, for a litany of reasons (that's a pun I guess). In such cases, a subpoena isn't in context: law enforcement have to investigate what has happened, to figure out if it needs to go to court. * Some investigations are important but do not meet the 'serious crime' threshold for forcing companies or parties to provide information. If you can imagine being the victim of a minor crime, that someone filmed and put on twitter, I'm sure you can imagine the local police may want a copy of the video before the tweet gets deleted - but also know that there will never be an international cooperative justice process. It's just a local issue. * Publically posted video is very common and often important, and it is not surprising that the police need a tool to download it. There are so many sites and web browser technologies, and the cops are not efficient spending their time coding youtube-dl equivalents. I feel quite strongly about youtube-dl being taken down for copyright infringement by the RIAA, but have tried to answer in an informative way. Sorry if it comes across harsh - no ill will intended :)