Easter egg: In the Special Edition DVD (with the white slipcover), if you go to the menu which tells about the equipment of "The Abyss", go to the "surface", where it talks about the wave and the Benthic Explorer. If you hit the up arrow on the wave, the plane flying overhead is highlighted. Select it to see a trailer for "True Lies," a movie that James Cameron directed.
Easter egg: In the Special Edition DVD (with the white slipcover), in the Imaging Station, if you go to the top of the stack of the videotapes and hit the right arrow button, the TV screen changes to say, "They mostly come at night. Mostly." Hit "enter" to see a trailer for "Aliens," a movie James Cameron directed.
Answer: Most of it was television news coverage about the increasing tensions between the US and USSR as it was playing out earlier in the movie. Additional archival footage from previous years' wars implied that the NTIs had been on Earth for quite a long time.