Previously a hidden Scratch Live "easter egg" feature, AM Mode is now an official Serato DJ feature. This feature allows you to hide the track details in the virtual deck from potential sniping playlist poachers.
Either enable this as an option in setup or quickly use the keyboard shortcut ALT + M to turn on / off. This feature hides the track and artist name on all playing decks.
Clicking on the track details area will quickly reveal your current playing track, but only for a split second.