No, I never got into trouble for shill bidding. Unfortunately, with ebay's anonymous bidding system it isn't provable either way. In fact when they started that crap on ebay they caused a lot of my faithful buyers to stop bidding because they couldn't see who they were bidding against them and assumed it was a shill bidder. It gets worse, if you were an early bidder, ebay has this neat feture called search by bidder. If someone finds out say you win a lot of cool stuff, they may put your name on a list and check to see if you are bidding on something they want, this is one of many reason among many why you may have lost auctions.
I sent out a lot of sco's because I have a wide range of selling prices I'd be willing to accept, generally cut off was around $25 on most items i sold, with that said I did end up selling a lot of things for the 9.95 minimum bid, all you have to do is wait and you'll eventually get something that your competing bidder forgot to snipe on.
Four disputes is easy to get when you make a few hundred sales in one week, especially when winning bidders are in places like Russia, Kazakhstan, and Romania. Also it's relatively easy for a major competing seller to get employees to register and bid just to file disputes, leave negative feedback, or simply rip off. I'm sure a seller with deep pockets could get a few JQ 6packs to do it for say 20 bucks as a last resort.
Bottom line ebay is fine if you are a Buyer, but if you are a seller, then it's false security. If you become too successful people will team up against you and get you kicked off simple as that.
This is why i won't accept paypal period, even through a third party, if it means quitting ebay for good, then so be it, the stress was literally killing me...
If you are very unlucky, this could happen, now the tactic is modified slightly to prevent you from stopping them. Basally the extorting user uses a hacked account, then if you don't comply a few weeks later they gang up on you using a ring of real accounts pulling paypal INR or SNAD scams..
YouTube - Ebay Feedback Extortion Scam Fraud Ring Exposed