The founder of the Proof of Brain tribe got into a disagreement with one or two Hive whales and they started massively DV’ing every post and comment he made with the stated purpose (by one of the account holders) of destroying his rep score, which is exactly what happened.
Although I disagree with the aforementioned behavior, I view this primarily as a front end issue. The front ends should allow folks to permanently unhide posts from trusted accounts and to set their own criteria for hiding posts from those with low rep scores.
As I've stated elsewhere (like here), we need to focus our efforts on Layer 2 solutions.
Improving the front-ends, to make them more customer-centric rather than blockchain-centric would be a great start, imo.