@comcol wrote:
Would think this is a very serious issue and hurting a lot of other business on Ebay who provide good service etc.
Since I can't investigate the seller in question, nor have I seen a specific seller have all negs removed inexplicably (I've seen / heard of some - just not all - negs disappearing), I can really only comment on the subject in general; however that is the point that makes me question the reasoning eBay would have for providing this level of protection for sellers. Impressions count for something, but it's the erosion of trust that would concern me, in that they talk a lot about retaining buyers at the cost of sellers, but this sort of thing is the opposite of that, allowing for there to be no warning or observation of consistent issues that dealing with a particular seller may present.
It's an unethical and hypocritical action for eBay to take when most other sellers, who try to get unfair / untrue negatives removed, are told "it's the buyer's opinion, suck it up".
Back before big box businesses became* so prevalent on eBay, there was a tool seller that was rather infamous both for problems buyers would experience, and having a lot of neg feedback removed, yet they still hovered between 98% and 99% most of the time, if memory serves, so it's definitely not a new issue, but perhaps an even more concerning one, despite the fact that negs don't affect a seller's account like they used to. These days, the known brands and retailers (I mean the national chain store types), can still have pretty shoddy feedback in the grand scheme of things, which makes me wonder what makes the sellers who get most (if not all) negs removed, so special? Are they effectively paying protection money? 
I mean, the practice would go against all of their (proclaimed) motives for the vast majority of recent policy changes and introductions, so there would have to be (methinks) some kind of other incentive for eBay to p**s off X buyers rather than risk p****ing off one seller.
*I award myself 10 bonus points for impromptu alliteration 
