Hey ya, OP here.

> It's been pointed out many times that anyone can create an NFT on a blockchain, and just because you own an NFT with a URL of http://example.com/example.jpg doesn't stop anyone else from creating another NFT with the same URL.

I addressed this under the section called "Common Objections". To sum up, even if someone else created an NFT contract with an entry pointing to the same URL, it likely wouldn't be viewed as legitimate.

I'm borrowing the term legitimate from Vitalik, which showed up on HN the other day. https://vitalik.ca/general/2021/03/23/legitimacy.html

Legitimate is whatever most people accept to the be case, in that social context. It doesn't matter if you don't view either contract as legitimate, because you're not a party to the social context where different parties are transacting. It only matters to those transacting in that social context. As long as the two parties can agree what is legitimate in a social context, then that's what works for them--kinda like how people agree on a price on an exchange. As long as a buyer and seller agree on a price, it doesn't matter if anyone else on the exchange thinks it's overvalued or undervalued. The aggregated agreement on which contract is legitimate over all transactions is what we collectively agree is legit.

> An NFT is 'genuine' solely because the artist says it is.

Sort of. It's more like a benevolent dictator position. A creator has the power to dictate which NFT is genuine because that power is conferred by the fans. There is no leader without followers.

But this power can be taken away. I'll refer to Vitalik's "Legitimate" post again.

"To better understand the force that we are getting at, another important example is the epic saga of Steem and Hive. In early 2020, Justin Sun bought Steem-the-company, which is not the same thing as Steem-the-blockchain but did hold about 20% of the STEEM token supply. The community, naturally, did not trust Justin Sun. So they made an on-chain vote to formalize what they considered to be a longstanding "gentleman's agreement" that Steem-the-company's coins were held in trust for the common good of Steem-the-blockchain and should not be used to vote. With the help of coins held by exchanges, Justin Sun made a counterattack, and won control of enough delegates to unilaterally control the chain. The community saw no further in-protocol options. So instead they made a fork of Steem-the-blockchain, called Hive, and copied over all of the STEEM token balances - except those, including Justin Sun's, which participated in the attack.

The lesson that we can learn from this situation is this: Steem-the-company never actually "owned" the coins. If they did, they would have had the practical ability to use, enjoy and abuse the coins in whatever way they wanted. But in reality, when the company tried to enjoy and abuse the coins in a way that the community did not like, they were successfully stopped. What's going on here is a pattern of a similar type to what we saw with the not-yet-issued Bitcoin and Ethereum coin rewards: the coins were ultimately owned not by a cryptographic key, but by some kind of social contract."

This is possible because the NFT is on-chain. It'd be much harder to do if Justin also controlled the centralized database with the NFT records.

Also, blockchains do add and enable things with NFTs. See the sections under interoperability in the post.

Thanks for pointing this out, I'll update the post later to be more clear.