It is also prevalent on crypto exchanges as the remnants of transactions that remain in wallets and can no longer be user or transferred.
This statement makes no sense to me. Maybe am I missing something?
The guy who sent the dust is watching. But the remaining balance he could be watching anyway, even if he didn't send any dust to the address.
If you don't use the remaining balance with other addresses in the same transaction you are just fine imo. Any thoughts?