That was also mentioned before and I'm pretty sure the supposed owner of the seven stopped by to let people know that they never actually did get seven as Zanz's claim that they were limited was made shortly before they got their sixth.
Unless, of course, the test has been done since then.
Whether they really are limited or not, Zanz has made it pretty clear that they are meant to be so if you are caught with seven or more in your deck, you will be in trouble.