It's really tiresome to ask each professor to use his slides for educational purposes as I have done here.
If a rights owner publishes a work online in a way that it is publicly accessible, but does not give a specific license (e.g. does not say 'you can download this for personal use'), is it legal to download (i.e. copy) that work for personal use, although there is no explicit license?*
*-Post updation given by @Brandin