The most common argument used in defense of mass surveillance is ‘If you have nothing to hide, you have nothing to fear’. Try saying that to women in the US states where abortion has suddenly become illegal. Say it to investigative journalists in authoritarian countries. Saying ‘I have nothing to hide’ means you stop caring about anyone fighting for their freedom. And one day, you might be one of them.
Easy: "You, the government, want me to show you all my data? Right after you show me (and everyone else) all your documents, including the "top secret" ones. Because you haven't done anything wrong, right?"