Earlier quoted context omitted.
It was used for tumbling, to the tune of $450m by the North Koreans. It's not a theoretical situation.
450m is a whopping 6% of all deposits on Tornado Cash[1]. The total percentage of illicit activity on the protocol is reported to be in the 10-30% range[2]. What percentage of activity in an E2EE chat application like Matrix is illicit? If a significant but minority percentage of its use is facilitating criminal discussion, should those open protocols also be sanctioned? [1] https://dune.com/poma/tornado-cash_1 [2] h…
It's also worth noting the headline of that link: "Crypto Mixer Usage Reaches All-time Highs in 2022, With Nation State Actors and Cybercriminals Contributing Significant Volume"
Quoting from later in that study, "Overall, if we label cybercriminal organizations with known nation state affiliations, we can see that these groups make up a significant and growing share of all illicit cryptocurrency sent to mixers."
It's not 10-30% as you summarized. It's 12% last year increasing to 23% this year, or nearly doubling from a 1/8 to 1/4 share.
This source does not support the position that illicit traffic is an insignificant share of mixer traffic.