It is impossible to contain leaks of private information. If you want to do private sexy slideshows of your shy wife, that's great, but think twice before you upload files or tags anywhere, particularly as you learn. By default, you are not connected to any servers and absolutely nothing is shared with other users-and you can't accidentally one-click your way to exposing your whole collection-but if you tag private files with real names and click to upload that data to a tag repository that other people have access to, the program won't try to stop you. Hydrus can be powerful, and you control everything.