Here is what I found when listing items on multiple accounts. Then checked it again, with a same result. Suspension. This happened with 8 accounts of 12. All suspended after listing was gone for a while, some after payment was received.
Some facts:
- I used whole new fully stealth ID. And I mean fully, IP

and everything.
- I listed whole different products in different category's, not same listing twice, so no same pictures etc.
- I added images thru imagehosting website, no mac etc. tracking could be done.
- I erased all metadata from pictures.
- I always erased all history, cookies etc. and changed my IP after I signed out from account.
Fact is that nothing was same. Half of accounts were +1month or more old, half was new.
So why my accounts were suspended?
Only thing I thought could be the reason after getting few suspensions was that I tracked the prices and progress of auctions thru link from my listing confirmation email or thru link that is added when you get a "user asking question" email. I newer logged to account when checking the items. After checking those listings thru those link's that directs you to the listing page, I logged to one account that was ended and all those accounts I made to list items that I checked thru email's link, got suspended, including the account I logged into.
Suspension for those four accounts were about that eBay wasn't sure of my ID and needed proof of that.
Simply I did this:
Listed with four accounts, erased all tracking data including changing IP after logout, tracked those items thru eBay's message where was link to listing page. After one ended, logged into account and few moments later got all four accounts suspended.
WHAT LINKED THOSE ACCOUNTS?
The fift IP that I was using when checking those items thru link on my email messages from eBay that I also used when logging into one of the accounts.
Did a recheck. Listed with three accounts. Let one end and got money from the first. Tracked thru links, but before logging to any account, changed IP. That one was OK. After second ended, checked both listings from emails links, and logged on one account, using same IP when checking and logging. Got suspensions after a while. Linked those accounts because of the IP I used to check items and after logging to that other account. Then listed with five stealth ID. Two are still going on. Three are ended and money gotten. Two of them intact.
With one I did final test;
I checked already ended and suspended accounts listing using unique IP thru the link on listing confirmation email. Then checked this accounts ended listing with the link of listing ended and item sold email and then logged in to that account. Got suspended after while.
So eBay now has some kind of new tracking software that is bundled somehow on the links address that comes in every email message that is send regarding that listing; listing confirmation, user question confimration and ending confimation.
If you use those links, software is recording all IP's used to go to listings page thru those links, and it doesn't matter if you check those items thru those links using only one IP (you don't get suspended like seen above), but if your IP is linked to one listing and you log on to different account using that IP, those both get suspended.
This is not a fact that eBay does have this kind of tracking in use, but it's a pritty good proof that they could have it. Hopefully this helps to people and hopefully you do understand this message how I ment it, even though my Eglish is little "OFF".
So for end I add that if I logged into account, I always cleared all tracking and changed IP. Same IP was newer used to log into two different accounts. Just added this because I don't want to hear about that kind of mistake.