This is why you power down some of your stake and move it to one or more anonymous curation accounts impossible to trace back to you. You have to do it off chain, of course. You need to go through an exchange. If everyone does that, they have nobody to lash out against. You don't have to even lose money doing this because you use the positive voting power to earn by curating (you can use SteemAuto to time your votes optimally) and the free 2.5 downvotes to snipe at the whales. They simply cannot revenge flag because you can't single out any curator by downvoting a piece of content. If they downvote everything you curate, they will very quickly run out of voting power even if they have millions of SP.
The method is completely foolproof and I'd love to see thousands of Steemians adopt it. If an entire beehive attacks a bear, they can kill it. No coordination required. Nobody has to be willing to take one for the team or anything like that.
I do have other accounts, but they can be traced back to me. I will consider this option, but there are enough low sp abusers to deal with for now.