In addition to knocking out 6880 kHz the high frequency trader high frequency data signal (HFTHFDS) knocks out the freebanders usually heard on 6900 kHz and other common peskie frequencies like 6919 kHz. I noticed an uptick in activity on 6800 kHz and nearby frequencies as well as 6950 kHz USB (!!) so they might have just moved to below 6850 kHz or so and above 6940 kHz or 6950 kHz. Seems like 6940-6950 kHz is another area to avoid with the Link-11 signal that is often found on 6941 kHz/6942 kHz. Probably not a good idea to QRM the US Navy, even if you do have a legit FCC Part 5 experimental license.
Not to mention MARS ops and the FEMA SHARES network that operates on 6910 kHz.