hotlinking

 Hotlinking  is the embedding of a resource (typically an image) from another website on your own site.

Downsides

 * The image might be (re)moved on the other website, leaving you with a broken image on the page.
 * https://youtu.be/lrwMja_VoM0?t=808
 * When your site gets a lot of traffic, you place a burden on the other website hosting the image.
 * The other website can see your traffic (or at least the people who request the image), and analyse basic information about your visitors.