I never heard this station broadcast, but......
I often hear a carrier on 6938, very strong here in Western WA, around S2-S4 out of 5, with some fading, nearly every late night / a.m., between 0500 and 1200 UTC, and it goes on for hours. Usually I hear it every night, depending on propagation. Because of its fading characteristics and its strengths often matching propagation, I am certain it's not RFI from anywhere around me. It's definitely a carrier.
In fact, it's still on as I type this at 1250 UTC.
I wonder if the carrier is associated with this station? I figured the carrier was an idle HFT transmitter.
I wouldn't think a pirate would send out a continuous carrier. Either way, out West, this frequency is a curious one for a pirate to have chosen.