Many authors put up their lecture notes online on their personal webpages, available for anyone to download, but many of them don't include a license. Are you allowed to download them or not (as someone not in their university/course, but they put it up on their webpage so anyone can download it)?
As an example, you can look for lecture notes on any topic, most of them won't have a license at the beginning.
(Specifically, I'm asking about Germany)