For my lesson I would make the students consider their personal information and how much they allow online.

(https://www.esafety.gov.au/kids/I-want-help-with/personal-information-online)

From the link provided I want the students to consider how they much they have of themselves online.
I would ask them questions as a class asking questions about online safety and if they practise it properly and ask if they can think of ways of improving their digital footprint.