Given serial numbers are used to register products, I would advise taking down the pictures. The message to buy new is helpful - but I'm not sure these serial numbers have much use in order to make sure new products are purchased. Stores can have items in inventory for a long time - yet the products have never been turned on after the factory (brand new). And it is unlikely someone will get your exact same keyboard - which is the only reason I can think of to have the serial number out there. Very little gain for such a one-in-a-thousand chance.

I have purchased 5 brand new keyboards from GuitarCenter since 2014 and none of those keyboards came brand new in the first place , NONE !!!!
In California it is illegal to resell return items as brand new , but GuitarCenter don't seem to care .

Example : My Roland Jupiter80 was damaged inside its undamaged box , the box was sealed too but NOT factory sealed !
I grew up with keyboards and I know what I'm talking about .

Not saying it doesn't happen - or didn't happen to you. Two issues here. One is serial number "identity theft" which I was attempting to assist with circumventing. The other is reselling used goods - which I still say is statistically low that these specific boards will end up in as wide of a net as you're casting for the warning. On balance - I thought a more generic warning about a particular vendor's bad practices may serve the overall better.

Again, all I was saying is that there are maybe tops 3 people who may be "bit" by these same keyboards - and they may reject them as you did. There is some gain - but marginal - and I it's just my humble opinion that the potential down-side of advertising serial numbers is worse than the intended cure here.

But I see your passion is higher than mine on this one, so I yield.