I am honestly not sure what would have to happen. Cynical part of me thinks a powerful senator needs to be seriously compromised, exposed and then, if he/she retains power, things might change a little.
Another option is to attempt to run yourself and be the change you want to see, but I have charisma of a wet blanket so it is not an option for me.
Well, sure, because "a breach" isn't anything scary in-and-of-itself, it's just the possibility of something scary.
If tons of people were suddenly victims of credit-card fraud or identity fraud due to the breaches, I don't think that would have been desensitizing in the same way, because that's a real consequence, not just the possibility of one.
Any one of these on its own should be enough but i'm not convinced the average person on the street could tell you what the deal was with any of these scandals.
E.g.: When a wave of echo users are blackmailed after their private conversations or sexcapades are snooped on, then you’d see outcry.
The only way something even as bad as what you stated will cause a change is if it affects politicians directly and they have personal messages and DM's with back-door dealings revealed that make them look bad. Sadly this is typically the only way things get done now is if there's some personal vested interest in the lawmaker.
Incognito mode does literally nothing. You're still doing your Google search from the same IP address so they still know it's you and store it the same as anything else.
South Park plot, Danish Trolls
Imagine being able to type in anyone's name and see their entire search history for the last 10 years. It would be total chaos. We'd have a constitutional amendment enforcing digital privacy within a few months.