I am a public school teacher only using my presentations for classroom use. Do I need to go through the trouble of citing every single image I pull from google? I never print them, only present or share.
As it is specified here, everything you create with Prezi, you own. Please know that it is up to you what content to insert, and Prezi would not be responsible for the content of the presentation.
As a graphic designer and (at best) amateur photographer, citing images is something I try to do as much as possible. There are not only legal implications but imagine if your image was being shared all over the place without permission, how would that make you feel? That said, I’m not perfect, so I sometimes wonder the same thing.
My personal opinion: 1/ cite if possible; it can be a tiny line of text at the bottom of the frame, usually not too distracting or time-consuming to do, 2/ if not possible: unless you’re using some highly publicized image & then selling that image globally, there’s likely slim chance you’ll get in trouble. It’s still a risk, even if small.