Marathon Digital (MARA) will label all of its bitcoins mined in the US with a "Made in USA" stamp. Why is this necessary? After all, the point of a mined block is that it is pure and not tied to an address.
Thus, miners cannot directly "label" bitcoins in the technical sense. Bitcoins are not tied to a specific address or source in the blockchain itself.
In this regard, the following issues should be noted:
1. At issue is tracking, not labeling: Companies like Marathon Digital do not label the bitcoins themselves, but rather track the blocks they mine.
2. Internal accounting: They keep their own records of which blocks their hardware has mined.
3. Coinbase transactions: When a miner mines a block, they are rewarded through what is called a coinbase transaction. This transaction is traceable.
4. External databases: companies can create external databases that link specific transactions or addresses to their activity.
5. Marketing: The claim that bitcoins are "Made in USA" is more of a marketing ploy than a technical reality.
6. No changes to the blockchain: It’s important to understand that there are no changes to the blockchain itself or the structure of bitcoin.
So "labeling" in this context is external tracking and marketing positioning, not a technical change to the bitcoins per se. Bitcoins remain immutable and fungible on the blockchain, regardless of who mined them.