What user do, or should do, isn't really a part of this argument. This is about Facebook violating agreements they made with governments or them violating laws. This is a subject of public prosecution. How users should respond is a different matter.
While dropping Facebook and Instagram is easy, WhatsApp is much harder. It's become the main communication medium for many, including a lot of group chats.
While you can abstain, it creates all kinds of awkwardness that I'm not willing to deal with currently.