Sharepoint and Security

Hi everyone,

we have differents customers using Sharepoint sites synchronized on their computers so they can see the folder in Windows Explorer.

My question is : how can you secure thoses datas when the people leave the company?

For example, is it possible the forbidden the functionnality "Allways keep on this computer"?

Or maybe using trusted computer in Entra?

I'm searching a solution to provide for 2 customers but i don't find a relevant solution.....

Thank you

Eric