Browsing their 'community' forum, it became clear that eBay have done this to loads of people recently, including many who had been members even longer than me. What disgusted me even more than this obnoxious privacy invasion was the number of people on the forum who'd actually sent eBay all the required documentation instead of telling them to go fuck themselves.
Luckily I had no uncleared payments in my account. So I've just stopped using eBay. It's just a pity there's no viable alternative. Nothing like a bit of healthy competition to help rein in the jaw-dropping arrogance of these mega-corporations