2134 UTC: ID given "You're listening to Pirate Radio Broadcast 2015 Holiday Special". QSL info provided with email address.
2135 UTC: ID again, back into music.
Got them at around a S7 on the K2SDR WebSDR. Thread title says they're in AM mode but the signal looks like USB (I don't see a carrier and only the upper side band)...and I'm only able to hear them in USB. Are they transmitting a reduced sideband with a carrier or did they just switch from AM to USB at some point?
2137 UTC: More Xmas music, good audio with some noise. Overall a great signal!
2138 UTC: "Merry Christmas boys" into advertisement for voice processor
2139 UTC: Back into "Simply Having a Wonderful Christmas Time"
looks to me like USB with an inaudible HF tone being generated to create an AM carrier (can tell by the aliasing in the audio in FFT AM)
edit: just after i posted this, the inaudible carrier ceased, perhaps RF cyclic feedback caused it ?
edit2: i agree with R4002, most likely someone tuning up.