Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I purchased off eBay just like thousands of others do I'm sure.
So you should have some emails from eBay and Paypal regarding the purchase. Even if you deleted the emails, your eBay history shows items dating back ~2 years. Paypal does as well. Showing the Apple store your Paypal invoice (which would also show the seller's info) would at least give them some indication your purchase was legit.
 
I purchased off eBay just like thousands of others do I'm sure. The seller didn't lock me out because the Mac was brand new in its plastic meaning how could they remotely put a lock on it. I locked myself out do to a find my Mac glitch and simply do not remember the pin I set


Most likely is the original owner, not the guy you bought off, locked you out and the update triggered it. You don't routinely set a lockout pin on FMM to forget it. Apple are being quite right to ask for Proof of ownership, this is exactly the scenario it is to cover.

eBay isn't an official Apple route to market, if this was a "new" machine then why do you think you got a good deal?
 

Exactly the same problem, but hardware reset no longer works and it doesn't allow me to disable the lock like the article suggests. Which leaves me with the option of going to google but that also does not work . Thanks for the reply

I'm confused, your reply here is saying your issue is the firmware password (right screen), but you keep talking about a four digit PIN, which is a FMM iCloud lockout (left screen). Which is it?

There is absolutely no way other of these got enabled automatically. To enable the firmware password you need to boot to recovery and run a utility from there to set it up. Then the FMM iCloud password is activated from an iCloud account, normally remotely when a machine is stolen.

Can you clarify which screen you are seeing?

efi-vs-icloud-lock.jpg
 
if it is the icloud thing might be some ransom-hack thing, there was a breach recently (xcode ghost). check if your icloud account is OK.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.