They have a weird habit of asking for information that can be literally decades out of date and forgotten. They just asked me for an old email address that was gone and dead for many years past. If I had not put it in my password safe, I would not have gotten access again.
eBay is likely working from information from semi-public sources; the sort of information that credit reporting agencies have access to, but that a random hacker most likely does not -- at least not without going to considerable expense to obtain: past addresses you have lived at, vehicles you have registered, phone numbers you have used, email addresses. The sorts of things that you might not be able to recall off the top of your head, but that you could identify if given a list of options to choose from.
As such, it will be difficult for you to change the sort of information that eBay (and other companies) use to verify your identity. It is probably much easier for you to keep track of that information yourself. If it was easy to update all those databases without cost, they would be vulnerable to hackers planting false information in order to spoof your identity. The point of such databases is not to have only your current address -- which is something that almost anyone can quickly look up for you -- but to have old addresses that you should be able to easily identify, but which others cannot without doing costly research.
