"On SKYKING (8992 or 11175 kHz USB) a call sign called “COLLAPSE” which has not been heard since 2001 has just broadcasted 4 messages to numbered stations/units in the last few minutes.

“FUXEBOX” and “Reykjavik,” have also broadcast in the last few days and they haven’t been heard since 1991 (collapse of the Soviet Union).

“COLLAPSE” has sent 3 messages in the last few minutes." Quote from Investment Watch website.
The article contains links to the signals being transmitted. I guess these were used with 911 and the fall of the Soviet Union. Twitter also went down. Not sure if it is back on line.