So the leaker will quickly find a way to remove the bitcoin watermark just like they do with traditional watermarks, instead of trying to cash out the coins.

So the leaker will quickly find a way to remove the bitcoin watermark just like they do with traditional watermarks, instead of trying to cash out the coins. The other counter-attack would be to distribute the scanning software to all the people who got the screeners so that there are a bunch of transactions and no way to know which one leaked vs. just took the $5. Probably too small an amount to get many takers, but it would muddy the waters even if only a few did it.