If photographs of people (taken from google image search) are used as resources during research (as conversation prompts during interviews/focus groups) without first obtaining permission (we're talking small scale masters thesis), can the findings of the research still be published? Even if the photographs themselves do not appear in the article? Could the researcher get into trouble re. copyright / ethics for using photos of people during their research without permission?
Any advice gratefully received!

If image is publicly available, then no one will really care.

I would just describe pictures generally in text (if needed)- e.g. image of man with children.