A common refrain in arguments that we don't need laws to protect privacy is that the market will take care of it. The market can't act against what it can't see. Privacy loss is often irreversible. A common refrain in arguments that we don't need to reject closed source software to protect privacy is that being closed source doesn't hide the behaviour, and people will still notice backdoors and privacy leaks. Sometim…
And there are cases where it's not practical for "people to notice." For instance: a privacy leak that only uses the cell network connection of a phone, which would avoid easily-sniffed connections.