I have looked at quite a few guitars from different sellers and noticed this a lot.
Check out the bid history on this item http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=110166677961&ssPageName=STRK:MEWA:IT&ih=001

I try to look up the bidders, but they don't exist.
And they all have a letter then *** and another letter.
Is someone using a program that generates fake bidders to shill bid ?
Quote by 8footsativaist

Perhaps the information under "protecting user id's" could be useful?

Or perhaps you're right.

Actually, I tried looking them up on "check a members feedback" as some of the bidders look like they have a lot of feedback, but when I try that, I get a message that there is a problem with the user ID.
I believe it is a new policy recently put in place by eBay to protect bidder's identity. I have some things listed for auction now. When I am not logged in, I see the same thing you are describing (*****f for example) on my auctions. When I log into my account, I can view the bidders' full username for my auctions though.
It seems like it should be something to do with the fact it's gone over a hundred dollars or so. They do that here on ebay UK as well, but it seems actually worse than what you're talking about because at least you can see part of the user id. Here we just get something that says 'bidder 1', 'bidder 2', 'bidder 3' etc. One would think that either way, it does indeed make shill bidding much, much easier! (especially since signup protocols for ebay accounts have long since been relaxed--back in the day you had to have an account provided by a certified ISP or else give credit card info! True, there were many ways around that...but...)
Thanks for the explanations, maybe I'm just paranoid, but it seemed fishy.
Why does the price go up in the bid history, when it is the same bidder ?
^-- Or it means somebody else bid, but didn't bid over the current high bidder's maximum bid. So that bumps up the current high bidder's current bid, without actually changing the high bidder.