I think your problem is that you're looking at very high-profile cases.
Most cases never make it that far. You have just enough that if any employer Googles someone before hiring, they don't get the job. If you have a half-dozen angry blog posts, or a local newspaper article or two, or a bunch of Twitter posts accusing you of something nasty, that's enough.
You're hiring someone for your team. If you have a choice between two job candidates, one where you see a half-dozen articles claiming they're racist, and one without, whom do you pick?
I know the choice I'd make. I don't want to deal with potential management problems.
Heck, even if you've sued a former employer (with good and legitimate reasons), why would someone pick you, knowing you're the sort of person who sues? Especially given I have no way to evaluate if the law suit was reasonable? Or if you've been involved in some conflict. Do I really want to sort out that mess? Or do I just give your resume a yellow flag, and pick someone without any yellow flags, if available.
In an up economy, where labor is scarce, you'll do fine. In a down economy where jobs are scarce, if you've got bad things about you on the internet, or even potentially yellow flags (e.g. some visible law suit or conflict), you've got a problem.
And yes, I can think of a couple of cases off the top of my head who have been through this, but I don't want to go Streisand Effect on people who'd much rather have normal, private lives.