When you say it like that - makes ton of sense like that. I thought people were more concerned that their transaction were accessible to the public. I like staying paranoid so ya this is important..
Discussion
Maybe an example of what they could mean is the unspent change output when making a transaction. Extreme example: if you’re an OG with 100 BTC and it’s all in one UTXO, you buy some swag online and give them your home physical address for shipping, they now see you have $10M and could show up to your door with a gun. There’s many ways this can go sideways. Just one example.