Yes, foz, that's the official eBay line. But they do absolutely nothing to prevent shill bidding.
A few years ago I was ripped off when I bought something - it was incomplete, packed badly and arrived in pieces - and the shredded paper packaging included dust mites as a free gift. Seller just gave me insults. Because it cost less than £15, eBay and Paypal would not act in the matter. I got the £5 purchase price back from the Post Office, but it cost me £12 for p&p.
I studied his sales and found that, if something was not reaching his desired price, his wife and his sister were bidding the items up. There was a particular fishing reel that he listed four times - first time it was withdrawn as broken, then his wife bought it, then his sister bought it, then he eventually sold it to a punter after both the wife and sister had placed bids on it. In addition, there were four eBay identities that regularly bid on his stuff, but had never bought anything, although they were members for over a year or so. I reported everything to eBay - not just the obvious bidding patterns, but with names and addresses and telephone numbers (you can pick things up sometimes), and eBay's response was that the info was over one month old, so they were unable to check it out.
There's a lot more I know - lots of people use "shadow identities" to bid on their items and force the price up.
The only thing eBay has done about shill bidding is made it harder to detect, by introducing privacy procedures that prevent you identifying other bidders.
You think that's bad - try telling them that an item is misdescribed.
What eBay say is not what eBay do - and when eBay/Paypal do act on a breach of rules, the action is often unfair and one-sided.